CO2 Weight Calculator
Calculate and understand the CO2 emissions (weight) associated with various activities, goods, or services. This calculator helps you estimate your carbon footprint in kilograms of CO2 equivalent.
Calculate CO2 Emissions
Driving (Petrol Car)
Flight (Economy)
Beef Consumption (1kg)
Electricity Usage (1 kWh)
Shipping (1 tonne-km)
Select the type of activity or item to calculate CO2 emissions for.
Enter the distance driven in kilometers.
Enter how many kilometers your car travels per litre of fuel.
Results copied!
Your Estimated CO2 Weight
— kg CO2e
Fuel Consumed: — litres
CO2 per Litre: — kg CO2e/litre
Fuel Weight: — kg
Formula: (Distance / Fuel Efficiency) * CO2 Emissions Factor per Unit of Fuel
This calculation provides an estimate of CO2 emissions in kilograms (CO2e) based on the provided inputs and standard emission factors.
CO2 Emission Factors by Activity
| Activity Type | Unit | CO2 Factor (kg CO2e per Unit) | Typical Range |
|---|---|---|---|
| Driving (Petrol Car) | Litre of Petrol | 2.31 | 2.0 – 2.7 |
| Flight (Economy) | Passenger-km | 0.15 | 0.1 – 0.3 |
| Beef Consumption | Kilogram | 27.0 | 20.0 – 60.0 |
| Electricity Usage | kWh | 0.45 | 0.1 – 1.0 (Varies by grid mix) |
| Shipping | Tonne-km | 0.02 | 0.01 – 0.05 |
CO2 Emissions Breakdown by Activity Type
What is a CO2 Weight Calculator?
A CO2 weight calculator is a tool designed to quantify the amount of carbon dioxide (CO2) and other greenhouse gases, expressed as CO2 equivalents (CO2e), released into the atmosphere as a result of a specific activity, product, or lifestyle choice. Essentially, it helps you measure your carbon footprint in terms of weight, typically in kilograms or tonnes.
Understanding the "weight" of CO2 emissions is crucial because CO2 is a gas, and its impact on climate change is directly related to its concentration in the atmosphere, which is influenced by the total mass emitted.
Who Should Use a CO2 Weight Calculator?
- Individuals: To understand the environmental impact of their daily activities, travel choices, consumption patterns, and dietary habits.
- Businesses: To measure the emissions from their operations, supply chains, product life cycles, and employee travel, aiding in sustainability reporting and reduction strategies.
- Educators and Students: As a learning tool to grasp the concepts of carbon footprints and climate change.
- Environmental Researchers: To gather data and perform analyses on emission sources.
Common Misconceptions
- "CO2 is just a gas, its weight doesn't matter": The weight is precisely what matters. Greenhouse gases trap heat, and their atmospheric concentration, determined by cumulative mass, drives global warming.
- "Calculators are too simplistic": While calculators use averages and simplified models, they provide essential estimations and highlight significant emission sources, serving as a starting point for more detailed analysis.
- "My individual contribution is too small to matter": Collective individual actions significantly impact overall emissions. Understanding your footprint empowers you to make informed choices that contribute to larger-scale change.
- "Only heavy industry causes CO2 emissions": Everyday activities like driving, flying, eating, and consuming electricity all contribute to CO2 emissions, often through complex supply chains.
CO2 Weight Calculator Formula and Mathematical Explanation
The core principle behind most CO2 weight calculators is the application of emission factors to specific quantities of activities or resources. The general formula can be expressed as:
Total CO2e Weight = Quantity of Activity/Resource × Emission Factor
Let's break this down with a common example: Calculating CO2 emissions from driving.
For driving, we often start with distance and fuel efficiency. To get to the weight of CO2, we need to know:
- How much fuel is consumed for the given distance?
- How much CO2 is emitted per unit of that fuel?
Step 1: Calculate Fuel Consumed
Fuel Consumed (litres) = Distance Driven (km) / Fuel Efficiency (km/litre)
Step 2: Calculate CO2 Emissions
Total CO2e Weight (kg) = Fuel Consumed (litres) × CO2 Emission Factor (kg CO2e / litre)
Combining these steps gives the overall formula implemented in our calculator for driving:
Total CO2e Weight = (Distance / Fuel Efficiency) × CO2 Emission Factor
Variable Explanations
| Variable | Meaning | Unit | Typical Range/Notes |
|---|---|---|---|
| Distance | The length of the journey or activity. | Kilometers (km) | Varies greatly; 10 km to thousands of km. |
| Fuel Efficiency | How far a vehicle can travel on a unit of fuel. | Kilometers per Litre (km/litre) | Petrol cars: 10-20 km/litre. Electric cars: measured in kWh/100km. |
| Quantity of Activity/Resource | The amount of a specific item or service consumed (e.g., kg of beef, kWh of electricity, tonnes-km for shipping). | Varies (kg, kWh, tonne-km, litre) | Depends heavily on the context. |
| CO2 Emission Factor | The average amount of CO2e emitted per unit of activity or resource. These are standardized values often provided by governmental or scientific bodies. | kg CO2e per Unit (e.g., kg CO2e/litre, kg CO2e/kWh, kg CO2e/kg) | Varies significantly by fuel type, energy source, agricultural practice, and transportation method. See table above for examples. |
| Fuel Weight | The actual mass of the fuel consumed. | Kilograms (kg) | Calculated from volume and density. |
| CO2 Weight | The primary output: total estimated mass of CO2e produced. | Kilograms (kg CO2e) | The final calculated emission value. |
Practical Examples (Real-World Use Cases)
Example 1: A Road Trip
Scenario: Sarah drives her petrol car from City A to City B, a distance of 500 km. Her car has a fuel efficiency of 12.5 km per litre.
Inputs:
- Activity Type: Driving (Petrol Car)
- Distance: 500 km
- Fuel Efficiency: 12.5 km/litre
Calculation Steps:
- Fuel Consumed: 500 km / 12.5 km/litre = 40 litres
- Fuel Weight: Assuming petrol density ~0.75 kg/litre, 40 litres * 0.75 kg/litre = 30 kg
- CO2 Emissions: 40 litres × 2.31 kg CO2e/litre = 92.4 kg CO2e
Result: Sarah's road trip generated an estimated 92.4 kg CO2e. This helps her understand the climate impact of her travel choice.
Example 2: Weekly Electricity Consumption
Scenario: A household uses 150 kWh of electricity in a week. The regional electricity grid's average emission factor is 0.45 kg CO2e per kWh.
Inputs:
- Activity Type: Electricity Usage
- Electricity Consumed: 150 kWh
Calculation Steps:
- CO2 Emissions: 150 kWh × 0.45 kg CO2e/kWh = 67.5 kg CO2e
Result: The household's electricity consumption for the week resulted in approximately 67.5 kg CO2e. This highlights the importance of energy efficiency and renewable energy sources.
How to Use This CO2 Weight Calculator
Our CO2 Weight Calculator is designed for ease of use, providing quick estimates of environmental impact.
- Select Activity Type: Choose the option that best describes the activity, product, or service you want to analyze from the dropdown menu.
- Enter Input Values: Fill in the required fields that appear based on your selection. These might include distance, fuel efficiency, quantity, or specific consumption figures. Use realistic numbers for accuracy.
- Validate Inputs: Pay attention to any inline error messages. Ensure your inputs are positive numbers and within reasonable ranges.
- Calculate: Click the "Calculate" button.
- Review Results: The primary result (Total CO2e Weight) will be prominently displayed. Key intermediate values and the formula used are also shown for transparency.
- Interpret: Understand the magnitude of the CO2 emissions. Compare results for different activities to identify areas where you can reduce your footprint. For instance, compare the CO2e of a long flight versus driving the same distance.
- Reset or Copy: Use the "Reset" button to clear the form and start over. Use "Copy Results" to easily share your findings or use them in reports.
How to Read Results
The main result is displayed in kilograms of CO2 equivalent (kg CO2e). This standardized unit allows for comparison across different greenhouse gases. Intermediate values provide context, such as how much fuel was used or the weight of that fuel.
Decision-Making Guidance
Use the calculator to compare options. For example:
- Is it better to fly or take a train for a specific distance?
- How does switching to a more fuel-efficient car impact your annual CO2 emissions?
- What is the carbon footprint of consuming 1 kg of beef versus 1 kg of lentils?
By quantifying these impacts, you can make more informed, sustainable choices.
Key Factors That Affect CO2 Weight Results
Several factors influence the accuracy and outcome of CO2 weight calculations:
- Emission Factor Accuracy: The primary driver is the emission factor used. These factors are averages and can vary based on specific technology, manufacturing processes, fuel quality, and geographic location (e.g., electricity grid mix). Using outdated or non-specific factors can lead to estimations that deviate from reality.
- Activity Specificity: Generic categories like "driving" or "flying" hide significant variations. A large SUV will emit more CO2 than a small hybrid car over the same distance. A long-haul flight has different per-km emissions than a short one due to takeoff/landing phases.
- Fuel Type and Quality: Different fuels have different carbon content. Even within the same fuel type (like petrol), variations in blend and additives can slightly alter emission rates.
- Operational Efficiency: How an activity is performed matters. Driving style (aggressive acceleration vs. smooth driving), proper vehicle maintenance, and efficient use of appliances directly impact fuel or energy consumption, thereby affecting total CO2 emissions.
- Lifecycle Emissions: Many calculators focus on the "use phase" (e.g., burning fuel). However, a full lifecycle assessment includes emissions from resource extraction, manufacturing, transportation, and disposal. For example, the production of electric car batteries has a significant carbon footprint, even though the car itself has zero tailpipe emissions.
- Scope of Calculation: Is the calculation only for direct emissions (Scope 1), or does it include indirect emissions from purchased energy (Scope 2) or supply chain emissions (Scope 3)? Our calculator primarily uses Scope 1 & 2 factors for simplicity.
- Data Granularity: Using precise, real-time data (like exact fuel consumption recorded by a vehicle's computer) will yield more accurate results than relying on manufacturer-stated fuel efficiency or generic distance estimates.
- Unit Consistency: Ensuring that the units of the quantity match the units of the emission factor is critical. Forgetting to convert km to miles, or kg to tonnes, will result in drastically incorrect figures.
Frequently Asked Questions (FAQ)
What's the difference between CO2 and CO2e?
CO2 (Carbon Dioxide) is the most prevalent greenhouse gas. CO2e (Carbon Dioxide Equivalent) is a unit used to express the global warming potential of all greenhouse gases relative to CO2. This allows for a single, comparable metric for total climate impact.
How accurate are these calculators?
CO2 weight calculators provide estimations based on average emission factors. While useful for understanding relative impacts and identifying major sources, they are not precise measurements of an individual's unique emissions. Actual emissions can vary due to specific circumstances.
Why is beef listed with such a high CO2 factor?
Beef production is resource-intensive, involving significant land use, methane emissions from livestock (a potent greenhouse gas), manure management, and feed production. These factors contribute to a much higher overall CO2e footprint per kilogram compared to plant-based foods or even other meats.
Does driving an electric car mean zero emissions?
Electric cars have zero tailpipe emissions, which significantly reduces local air pollution. However, their overall carbon footprint depends on the source of the electricity used to charge them. If the electricity comes from fossil fuels, there are still associated upstream emissions.
How can I reduce my CO2 footprint based on these calculations?
Identify the activities with the highest CO2 emissions from the calculator results. Focus on reducing these, for example: driving less, choosing efficient transport, reducing meat consumption, improving home energy efficiency, or opting for renewable energy sources where possible.
What does "tonne-km" mean for shipping?
"Tonne-kilometer" (tkm) is a unit of measure for freight transport volume. It represents moving one tonne of cargo over a distance of one kilometer. It accounts for both the weight of the goods and the distance they are transported.
Are the emission factors for electricity the same everywhere?
No, electricity emission factors vary significantly by region and country, depending on the primary sources used in the energy grid mix (e.g., coal, natural gas, hydro, solar, wind). Grids heavily reliant on fossil fuels have higher emission factors.
Can I use this calculator for business fleet emissions?
Yes, you can adapt this calculator for business fleets by inputting the distances traveled by different vehicle types and their respective fuel efficiencies. For comprehensive business reporting, consider more specialized carbon accounting tools that also factor in Scope 2 and Scope 3 emissions.
Related Tools and Internal Resources
- Fuel Cost Calculator: Estimate your expenses based on fuel consumption and price.
- Energy Efficiency Calculator: Assess potential savings from home energy upgrades.
- Sustainable Diet Guide: Learn about the environmental impact of different food choices.
- Carbon Offsetting Options: Explore ways to compensate for unavoidable emissions.
- Business Carbon Footprint Calculator: A more detailed tool for corporate emission tracking.
- Understanding Climate Change: An introductory article on global warming causes and effects.
';
html += '';
html += ";
html += '
';
html += 'Enter the distance in kilometers.
';
html += '';
html += '';
html += '';
html += ";
html += '
';
} else if (activityType === 'flying') {
html += 'Enter how many kilometers your vehicle travels per litre of fuel.
';
html += '';
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html += '';
html += ";
html += '
';
} else if (activityType === 'beef') {
html += 'Enter the distance of the flight in kilometers.
';
html += '';
html += '';
html += ''; // Reusing distanceLabel for quantity for beef
html += ";
html += '
';
} else if (activityType === 'electricity') {
html += 'Enter the weight of beef consumed in kilograms.
';
html += '';
html += '';
html += ''; // Reusing distanceLabel for quantity for electricity
html += ";
html += '
';
} else if (activityType === 'shipping') {
html += 'Enter the electricity consumed in kilowatt-hours (kWh).
';
html += '';
html += '';
html += ''; // Reusing distanceLabel for quantity for shipping
html += ";
html += '
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}
dynamicInputsDiv.innerHTML = html;
calculateCO2(); // Recalculate after changing inputs
updateChart(); // Update chart after changing inputs
}
function validateInput(id, min, max, errorId, specificCheckFn = null) {
var input = document.getElementById(id);
var value = parseFloat(input.value);
var errorDiv = document.getElementById(errorId);
errorDiv.textContent = "; // Clear previous error
if (isNaN(value)) {
errorDiv.textContent = 'Please enter a valid number.';
return false;
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if (value max) {
errorDiv.textContent = 'Value is too high.';
return false;
}
if (specificCheckFn && !specificCheckFn(value)) {
// Specific error message handled within specificCheckFn
return false;
}
return true;
}
function calculateCO2() {
var activityType = document.getElementById('activityType').value;
var config = emissionFactors[activityType];
var primaryResult = document.getElementById('primary-result');
var fuelConsumedDiv = document.getElementById('fuelConsumed');
var co2PerLitreDiv = document.getElementById('co2PerLitre');
var fuelWeightDiv = document.getElementById('fuelWeight');
var formulaExplanation = document.querySelector('.formula-explanation');
// Reset results
primaryResult.innerHTML = '– kg CO2e';
fuelConsumedDiv.innerHTML = 'Fuel Consumed: — litres';
co2PerLitreDiv.innerHTML = 'CO2 per Litre: — kg CO2e/litre';
fuelWeightDiv.innerHTML = 'Fuel Weight: — kg';
// Clear all error messages initially
document.getElementById('distanceError').textContent = ";
if (document.getElementById('fuelEfficiency')) document.getElementById('fuelEfficiencyError').textContent = ";
if (document.getElementById('quantity')) document.getElementById('quantityError').textContent = ";
var isValid = true;
var distance = 0;
var fuelEfficiency = 0;
var quantity = 0;
var fuelConsumed = 0;
var fuelWeight = 0;
var co2Emissions = 0;
var co2PerUnit = config.factor;
if (activityType === 'driving') {
var isDistanceValid = validateInput('distance', 0, undefined, 'distanceError');
var isFuelEfficiencyValid = validateInput('fuelEfficiency', 0.1, undefined, 'fuelEfficiencyError');
if (!isDistanceValid || !isFuelEfficiencyValid) {
isValid = false;
} else {
distance = parseFloat(document.getElementById('distance').value);
fuelEfficiency = parseFloat(document.getElementById('fuelEfficiency').value);
fuelConsumed = distance / fuelEfficiency;
fuelWeight = fuelConsumed * 0.75; // Assuming petrol density ~0.75 kg/litre
co2Emissions = fuelConsumed * co2PerUnit;
formulaExplanation.textContent = 'Formula: (Distance / Fuel Efficiency) * CO2 Emissions Factor per Litre';
}
} else if (activityType === 'flying') {
var isDistanceValid = validateInput('distance', 0, undefined, 'distanceError');
if (!isDistanceValid) {
isValid = false;
} else {
distance = parseFloat(document.getElementById('distance').value);
co2Emissions = distance * co2PerUnit;
fuelConsumedDiv.style.display = 'none';
co2PerLitreDiv.style.display = 'none';
fuelWeightDiv.style.display = 'none';
formulaExplanation.textContent = 'Formula: Distance (passenger-km) * CO2 Emissions Factor per Passenger-km';
}
} else if (activityType === 'beef' || activityType === 'electricity' || activityType === 'shipping') {
var isQuantityValid = validateInput('quantity', 0, undefined, 'quantityError');
if (!isQuantityValid) {
isValid = false;
} else {
quantity = parseFloat(document.getElementById('quantity').value);
co2Emissions = quantity * co2PerUnit;
fuelConsumedDiv.style.display = 'none';
co2PerLitreDiv.style.display = 'none';
fuelWeightDiv.style.display = 'none';
var unitLabel = config.unit === 'kg' ? 'kg' : (config.unit === 'kWh' ? 'kWh' : 'tonne-km');
var quantityLabel = activityType === 'beef' ? 'Beef Consumed' : (activityType === 'electricity' ? 'Electricity Used' : 'Shipping Volume');
formulaExplanation.textContent = 'Formula: ' + quantityLabel + ' (' + unitLabel + ') * CO2 Emissions Factor per ' + unitLabel;
}
}
if (isValid && co2Emissions > 0) {
primaryResult.innerHTML = co2Emissions.toFixed(2) + ' kg CO2e';
if (activityType === 'driving') {
fuelConsumedDiv.innerHTML = 'Fuel Consumed: ' + fuelConsumed.toFixed(2) + ' litres';
co2PerLitreDiv.innerHTML = 'CO2 per Litre: ' + co2PerUnit.toFixed(2) + ' kg CO2e/litre';
fuelWeightDiv.innerHTML = 'Fuel Weight: ' + fuelWeight.toFixed(2) + ' kg';
fuelConsumedDiv.style.display = 'block';
co2PerLitreDiv.style.display = 'block';
fuelWeightDiv.style.display = 'block';
} else {
fuelConsumedDiv.style.display = 'none';
co2PerLitreDiv.style.display = 'none';
fuelWeightDiv.style.display = 'none';
}
} else if (isValid && co2Emissions === 0) {
primaryResult.innerHTML = '0.00 kg CO2e';
if (activityType === 'driving') {
fuelConsumedDiv.innerHTML = 'Fuel Consumed: 0.00 litres';
co2PerLitreDiv.innerHTML = 'CO2 per Litre: ' + co2PerUnit.toFixed(2) + ' kg CO2e/litre';
fuelWeightDiv.innerHTML = 'Fuel Weight: 0.00 kg';
fuelConsumedDiv.style.display = 'block';
co2PerLitreDiv.style.display = 'block';
fuelWeightDiv.style.display = 'block';
} else {
fuelConsumedDiv.style.display = 'none';
co2PerLitreDiv.style.display = 'none';
fuelWeightDiv.style.display = 'none';
}
}
updateChart();
}
function resetCalculator() {
document.getElementById('activityType').value = 'driving';
updateCalculatorOptions();
calculateCO2();
// Clear any lingering error messages
document.getElementById('distanceError').textContent = ";
if (document.getElementById('fuelEfficiency')) document.getElementById('fuelEfficiencyError').textContent = ";
if (document.getElementById('quantity')) document.getElementById('quantityError').textContent = ";
}
function copyResults() {
var activityType = document.getElementById('activityType').value;
var config = emissionFactors[activityType];
var primaryResultText = document.getElementById('primary-result').innerText;
var fuelConsumedText = document.getElementById('fuelConsumed').innerText;
var co2PerLitreText = document.getElementById('co2PerLitre').innerText;
var fuelWeightText = document.getElementById('fuelWeight').innerText;
var formulaText = document.querySelector('.formula-explanation').innerText;
var copyText = "— CO2 Weight Calculation Results —\n";
copyText += "Activity Type: " + activityType.charAt(0).toUpperCase() + activityType.slice(1) + "\n";
if (activityType === 'driving') {
copyText += "Distance: " + document.getElementById('distance').value + " km\n";
copyText += "Fuel Efficiency: " + document.getElementById('fuelEfficiency').value + " km/litre\n";
copyText += primaryResultText + "\n";
copyText += fuelConsumedText + "\n";
copyText += co2PerLitreText + "\n";
copyText += fuelWeightText + "\n";
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copyText += "Distance: " + document.getElementById('distance').value + " km\n";
copyText += primaryResultText + "\n";
} else if (activityType === 'beef' || activityType === 'electricity' || activityType === 'shipping') {
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copyText += primaryResultText + "\n";
}
copyText += "\n" + formulaText + "\n";
copyText += "Key Assumptions:\n";
if (activityType === 'driving') copyText += "- Petrol density assumed at 0.75 kg/litre.\n";
copyText += "- Emission factors are based on averages and may vary.\n";
// Create a temporary textarea element
var textArea = document.createElement("textarea");
textArea.value = copyText;
textArea.style.position = "fixed"; // Avoid scrolling to bottom of page in MS Edge.
textArea.style.top = 0;
textArea.style.left = 0;
textArea.style.width = '2em';
textArea.style.height = '2em';
textArea.style.padding = '0';
textArea.style.border = 'none';
textArea.style.outline = 'none';
textArea.style.boxShadow = 'none';
document.body.appendChild(textArea);
textArea.focus();
textArea.select();
try {
var successful = document.execCommand('copy');
var msg = successful ? 'successful' : 'unsuccessful';
console.log('Copying text command was ' + msg);
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confirmationDiv.style.display = 'block';
setTimeout(function() {
confirmationDiv.style.display = 'none';
}, 2000);
} catch (err) {
console.log('Unable to copy text.', err);
}
document.body.removeChild(textArea);
}
function toggleFaq(element) {
var faqItem = element.closest('.faq-item');
faqItem.classList.toggle('open');
var answer = faqItem.querySelector('.answer');
if (faqItem.classList.contains('open')) {
answer.style.display = 'block';
} else {
answer.style.display = 'none';
}
}
// Chart Initialization and Update
var co2Chart;
var chartData = {
labels: ['Driving', 'Flying', 'Beef', 'Electricity', 'Shipping'],
datasets: [{
label: 'Estimated CO2e Emissions (kg)',
data: [0, 0, 0, 0, 0],
backgroundColor: [
'rgba(0, 74, 153, 0.7)',
'rgba(40, 167, 69, 0.7)',
'rgba(255, 193, 7, 0.7)',
'rgba(108, 117, 125, 0.7)',
'rgba(220, 53, 69, 0.7)'
],
borderColor: [
'rgba(0, 74, 153, 1)',
'rgba(40, 167, 69, 1)',
'rgba(255, 193, 7, 1)',
'rgba(108, 117, 125, 1)',
'rgba(220, 53, 69, 1)'
],
borderWidth: 1
}]
};
function updateChart() {
var currentActivity = document.getElementById('activityType').value;
var currentEmission = parseFloat(document.getElementById('primary-result').innerText.replace(/ kg CO2e|-/g, ")) || 0;
var ctx = document.getElementById('co2Chart').getContext('2d');
if (co2Chart) {
co2Chart.destroy();
}
// Update specific activity data point
var dataPoints = [0, 0, 0, 0, 0];
var labels = ['Driving', 'Flying', 'Beef', 'Electricity', 'Shipping'];
var index = labels.indexOf(currentActivity.charAt(0).toUpperCase() + currentActivity.slice(1));
if (index !== -1) {
dataPoints[index] = currentEmission;
}
// Fetch data from table for a static representation if current calculation is 0
var emissionFactorsTable = {
'Driving': 2.31,
'Flying': 0.15,
'Beef': 27.0,
'Electricity': 0.45,
'Shipping': 0.02
};
var exampleDataPoints = [];
labels.forEach(function(label) {
var factor = emissionFactorsTable[label];
if (label === 'Driving') {
// Example: 100km at 15 km/l
exampleDataPoints.push((100 / 15) * factor);
} else if (label === 'Flying') {
// Example: 1000 passenger-km
exampleDataPoints.push(1000 * factor);
} else if (label === 'Beef') {
// Example: 1kg beef
exampleDataPoints.push(1 * factor);
} else if (label === 'Electricity') {
// Example: 100 kWh
exampleDataPoints.push(100 * factor);
} else if (label === 'Shipping') {
// Example: 1000 tonne-km
exampleDataPoints.push(1000 * factor);
}
});
chartData.datasets[0].data = dataPoints; // Current calculation
// Optionally, create a second dataset for comparison or base rates if needed.
// For simplicity here, we'll just use the current calculation.
co2Chart = new Chart(ctx, {
type: 'bar', // Using bar chart for better comparison
data: chartData,
options: {
responsive: true,
maintainAspectRatio: false,
scales: {
y: {
beginAtZero: true,
title: {
display: true,
text: 'Weight of CO2e (kg)'
}
},
x: {
title: {
display: true,
text: 'Activity Type'
}
}
},
plugins: {
legend: {
position: 'top',
},
title: {
display: true,
text: 'Your Current Activity\'s CO2e Contribution'
}
}
}
});
}
// Initial setup on page load
window.onload = function() {
updateCalculatorOptions();
calculateCO2();
// Dynamically create canvas element if it doesn't exist, or ensure it's ready
var canvasContainer = document.getElementById('co2Chart').parentNode;
if (!document.getElementById('co2Chart')) {
var canvas = document.createElement('canvas');
canvas.id = 'co2Chart';
canvasContainer.appendChild(canvas);
}
// Initialize chart
updateChart();
};
// Need to include Chart.js library or implement a simple chart renderer
// For this standalone HTML, we'll assume Chart.js is available.
// If not, a pure SVG or Canvas implementation would be required.
// Since the prompt specified NO external libraries, and native canvas API is complex for
// full charting, we'll add a note that for a real-world scenario, Chart.js would be used.
// HOWEVER, adhering strictly to "NO external libraries", I will simulate basic rendering.
// START: Pure Canvas Rendering (simplified, no complex charting library)
function renderSimpleChart(ctx, data, labels, colors) {
var chartHeight = ctx.canvas.height;
var chartWidth = ctx.canvas.width;
var barWidth = (chartWidth * 0.8) / data.length; // 80% width for bars, divide by number of bars
var xStart = chartWidth * 0.1; // Start drawing bars 10% from the left
var yAxisHeight = chartHeight * 0.8; // 80% height for the Y-axis scale
var yAxisStart = chartHeight * 0.1; // Start drawing Y-axis 10% from the top
// Find max value for scaling
var maxValue = 0;
for (var i = 0; i maxValue) maxValue = data[i];
}
if (maxValue === 0) maxValue = 1; // Prevent division by zero if all data is 0
// Clear canvas
ctx.clearRect(0, 0, chartWidth, chartHeight);
// Draw Bars
ctx.fillStyle = '#004a99'; // Default color for context
for (var i = 0; i < data.length; i++) {
var barHeight = (data[i] / maxValue) * yAxisHeight;
var x = xStart + i * barWidth + (barWidth * 0.1); // Add slight gap between bars
var y = yAxisStart + yAxisHeight – barHeight;
ctx.fillStyle = colors[i % colors.length] || '#cccccc'; // Use provided colors
ctx.fillRect(x, y, barWidth * 0.8, barHeight); // Draw bar
// Draw label below bar
ctx.fillStyle = '#333';
ctx.font = '10px Arial';
ctx.textAlign = 'center';
ctx.fillText(labels[i], x + (barWidth * 0.4), chartHeight – 10);
// Draw value above bar
ctx.fillStyle = '#000';
ctx.font = '11px Arial';
ctx.fillText(data[i].toFixed(1), x + (barWidth * 0.4), y – 5);
}
// Draw Y-axis Scale (simplified)
ctx.strokeStyle = '#333';
ctx.lineWidth = 1;
ctx.beginPath();
ctx.moveTo(xStart, yAxisStart);
ctx.lineTo(xStart, yAxisStart + yAxisHeight);
ctx.stroke();
// Draw scale markers and labels
var numTicks = 5;
for (var i = 0; i <= numTicks; i++) {
var yPos = yAxisStart + yAxisHeight – (i / numTicks) * yAxisHeight;
ctx.moveTo(xStart – 5, yPos);
ctx.lineTo(xStart, yPos);
ctx.stroke();
ctx.fillStyle = '#333';
ctx.font = '10px Arial';
ctx.textAlign = 'right';
ctx.fillText((i * maxValue / numTicks).toFixed(0), xStart – 10, yPos + 4);
}
// Draw title/legend (simplified)
ctx.fillStyle = '#004a99';
ctx.font = '14px Arial';
ctx.textAlign = 'center';
ctx.fillText('Estimated CO2e Emissions (kg)', chartWidth / 2, yAxisStart / 2);
}
// Replace Chart.js rendering with the simple canvas rendering
function updateChart() {
var activityType = document.getElementById('activityType').value;
var currentEmission = parseFloat(document.getElementById('primary-result').innerText.replace(/ kg CO2e|-/g, '')) || 0;
var ctx = document.getElementById('co2Chart').getContext('2d');
// Data for the chart
var labels = ['Driving', 'Flying', 'Beef', 'Electricity', 'Shipping'];
var colors = [
'rgba(0, 74, 153, 0.7)',
'rgba(40, 167, 69, 0.7)',
'rgba(255, 193, 7, 0.7)',
'rgba(108, 117, 125, 0.7)',
'rgba(220, 53, 69, 0.7)'
];
// Calculate base example emissions for comparison if needed, or just show current.
// For this, we'll just show the current calculation's value for its category.
var dataValues = [0, 0, 0, 0, 0];
var emissionFactorsTable = {
'Driving': { factor: 2.31, defaultDist: 100, defaultEff: 15 },
'Flying': { factor: 0.15, defaultDist: 1000 },
'Beef': { factor: 27.0, defaultDist: 1 },
'Electricity': { factor: 0.45, defaultDist: 100 },
'Shipping': { factor: 0.02, defaultDist: 1000 }
};
// Populate dataValues based on current selection
var selectedLabel = activityType.charAt(0).toUpperCase() + activityType.slice(1);
var index = labels.indexOf(selectedLabel);
if (index !== -1) {
dataValues[index] = currentEmission;
}
renderSimpleChart(ctx, dataValues, labels, colors);
}
// END: Pure Canvas Rendering
Enter the total cargo weight in tonnes multiplied by the distance in km (tonne-km).
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html += '';
html += '