Unit Conversion Calculator
Select Conversion Type
Length
Weight
Temperature
Volume
Conversion Details
Result
—Understanding Unit Conversions
Unit conversion is the process of changing a measurement from one unit of measurement to another. This is a fundamental skill in various fields, including science, engineering, cooking, and everyday life. Accurate conversions ensure consistency and prevent errors, especially when working with data from different sources or following instructions from different regions.
Common Conversion Types and Their Math
This calculator handles several common types of conversions:
Length Conversions:
Converts between units of distance, such as meters, kilometers, feet, inches, miles, etc.
- Meters to Feet: Multiply meters by 3.28084.
- Feet to Meters: Multiply feet by 0.3048.
- Kilometers to Miles: Multiply kilometers by 0.621371.
- Miles to Kilometers: Multiply miles by 1.60934.
- Inches to Centimeters: Multiply inches by 2.54.
- Centimeters to Inches: Multiply centimeters by 0.393701.
Weight (Mass) Conversions:
Converts between units of mass, such as kilograms, grams, pounds, ounces, tons, etc.
- Kilograms to Pounds: Multiply kilograms by 2.20462.
- Pounds to Kilograms: Multiply pounds by 0.453592.
- Grams to Ounces: Multiply grams by 0.035274.
- Ounces to Grams: Multiply ounces by 28.3495.
- Metric Tons to US Tons: Multiply metric tons by 1.10231.
- US Tons to Metric Tons: Multiply US tons by 0.907185.
Temperature Conversions:
Converts between different temperature scales like Celsius, Fahrenheit, and Kelvin. These often involve both multiplication and addition/subtraction.
- Celsius to Fahrenheit: (Celsius × 9/5) + 32
- Fahrenheit to Celsius: (Fahrenheit – 32) × 5/9
- Celsius to Kelvin: Celsius + 273.15
- Kelvin to Celsius: Kelvin – 273.15
- Fahrenheit to Kelvin: (Fahrenheit – 32) × 5/9 + 273.15
- Kelvin to Fahrenheit: (Kelvin – 273.15) × 9/5 + 32
Volume Conversions:
Converts between units of volume, such as liters, milliliters, gallons, quarts, pints, fluid ounces, etc.
- Liters to Gallons (US): Multiply liters by 0.264172.
- Gallons (US) to Liters: Multiply gallons by 3.78541.
- Liters to Quarts (US): Multiply liters by 1.05669.
- Quarts (US) to Liters: Multiply quarts by 0.946353.
- Milliliters to Fluid Ounces (US): Multiply milliliters by 0.033814.
- Fluid Ounces (US) to Milliliters: Multiply fluid ounces by 29.5735.
Why Use a Unit Conversion Calculator?
- Accuracy: Avoids manual calculation errors.
- Speed: Quickly converts values without needing lookup tables.
- Versatility: Handles multiple unit types and scales.
- Learning: Helps users understand the relationships between different units.
- Cross-Disciplinary Use: Essential for anyone working with international standards or data.
Whether you're a student, a professional, or just curious, this calculator provides a reliable tool for all your unit conversion needs.
Meters
Kilometers
Feet
Inches
Miles
Meters
Kilometers
Feet
Inches
Miles
`;
} else if (type === "weight") {
html = `
Kilograms
Grams
Pounds
Ounces
Metric Tons
US Tons
Kilograms
Grams
Pounds
Ounces
Metric Tons
US Tons
`;
} else if (type === "temperature") {
html = `
Celsius (°C)
Fahrenheit (°F)
Kelvin (K)
Celsius (°C)
Fahrenheit (°F)
Kelvin (K)
`;
} else if (type === "volume") {
html = `
Liters
Milliliters
US Gallons
US Quarts
US Pints
US Fluid Ounces
Liters
Milliliters
US Gallons
US Quarts
US Pints
US Fluid Ounces
`;
}
inputSection.innerHTML = html;
}
function calculateConversion() {
var type = document.getElementById("conversionType").value;
var resultElement = document.getElementById("conversionResult");
resultElement.textContent = "–";
var value, fromUnit, toUnit, convertedValue;
if (type === "length") {
value = parseFloat(document.getElementById("lengthValue").value);
fromUnit = document.getElementById("lengthUnit").value;
toUnit = document.getElementById("lengthTargetUnit").value;
if (isNaN(value)) {
resultElement.textContent = "Invalid input";
return;
}
var factors = {
meters: 1,
kilometers: 0.001,
feet: 0.3048,
inches: 0.0254,
miles: 0.000621371
};
var valueInMeters = value / factors[fromUnit];
convertedValue = valueInMeters / factors[toUnit];
resultElement.textContent = convertedValue.toFixed(4);
} else if (type === "weight") {
value = parseFloat(document.getElementById("weightValue").value);
fromUnit = document.getElementById("weightUnit").value;
toUnit = document.getElementById("weightTargetUnit").value;
if (isNaN(value)) {
resultElement.textContent = "Invalid input";
return;
}
var factors = {
kg: 1,
grams: 0.001,
lbs: 0.453592,
oz: 0.0283495,
metric_ton: 0.000001,
us_ton: 0.000453592
};
var valueInKg = value / factors[fromUnit];
convertedValue = valueInKg / factors[toUnit];
resultElement.textContent = convertedValue.toFixed(4);
} else if (type === "temperature") {
value = parseFloat(document.getElementById("tempValue").value);
fromUnit = document.getElementById("tempUnit").value;
toUnit = document.getElementById("tempTargetUnit").value;
if (isNaN(value)) {
resultElement.textContent = "Invalid input";
return;
}
var celsiusValue;
if (fromUnit === "celsius") {
celsiusValue = value;
} else if (fromUnit === "fahrenheit") {
celsiusValue = (value – 32) * 5 / 9;
} else if (fromUnit === "kelvin") {
celsiusValue = value – 273.15;
}
if (toUnit === "celsius") {
convertedValue = celsiusValue;
} else if (toUnit === "fahrenheit") {
convertedValue = (celsiusValue * 9 / 5) + 32;
} else if (toUnit === "kelvin") {
convertedValue = celsiusValue + 273.15;
}
resultElement.textContent = convertedValue.toFixed(2);
} else if (type === "volume") {
value = parseFloat(document.getElementById("volumeValue").value);
fromUnit = document.getElementById("volumeUnit").value;
toUnit = document.getElementById("volumeTargetUnit").value;
if (isNaN(value)) {
resultElement.textContent = "Invalid input";
return;
}
var factors = {
liters: 1,
ml: 0.001,
gallons_us: 0.264172,
quarts_us: 1.05669,
pints_us: 2.11337,
fl_oz_us: 33.814
};
var valueInLiters = value / factors[fromUnit];
convertedValue = valueInLiters / factors[toUnit];
resultElement.textContent = convertedValue.toFixed(4);
}
// Update result units
var fromUnitDisplay = document.querySelector(`#${type}Unit option[value='${fromUnit}']`)?.text || fromUnit;
var toUnitDisplay = document.querySelector(`#${type}TargetUnit option[value='${toUnit}']`)?.text || toUnit;
if (type === "temperature") {
resultElement.textContent += ` ${toUnitDisplay}`;
} else if (type === "length" || type === "weight" || type === "volume") {
resultElement.textContent += ` ${toUnitDisplay}`;
}
}
// Initialize inputs on page load
document.addEventListener('DOMContentLoaded', updateInputs);