Meter (m)
Kilometer (km)
Centimeter (cm)
Millimeter (mm)
Mile (mi)
Yard (yd)
Foot (ft)
Inch (in)
Kilogram (kg)
Gram (g)
Milligram (mg)
Tonne (t)
Pound (lb)
Ounce (oz)
Liter (L)
Milliliter (mL)
Cubic Meter (m³)
US Gallon (gal)
US Quart (qt)
US Pint (pt)
US Cup (cup)
US Fluid Ounce (fl oz)
Meter (m)
Kilometer (km)
Centimeter (cm)
Millimeter (mm)
Mile (mi)
Yard (yd)
Foot (ft)
Inch (in)
Kilogram (kg)
Gram (g)
Milligram (mg)
Tonne (t)
Pound (lb)
Ounce (oz)
Liter (L)
Milliliter (mL)
Cubic Meter (m³)
US Gallon (gal)
US Quart (qt)
US Pint (pt)
US Cup (cup)
US Fluid Ounce (fl oz)
Understanding Metric and Imperial Unit Conversions
This calculator helps you convert values between various units of measurement, primarily focusing on metric units and their common imperial counterparts. Accurate unit conversion is crucial in many fields, including science, engineering, manufacturing, cooking, and everyday tasks.
How it Works: The Conversion Logic
The calculator works by converting your input value into a standardized base unit, and then converting that base unit into the target unit. For simplicity and accuracy, we use established conversion factors.
Length: The base unit is the meter (m). Conversions involve multiplying or dividing by factors like 1000 (for kilometers), 0.01 (for centimeters), etc. For imperial units, we use standard equivalences like 1 mile ≈ 1609.34 meters, 1 foot = 0.3048 meters, 1 inch = 0.0254 meters.
Mass: The base unit is the kilogram (kg). Conversions are based on powers of 10 for metric units (1 kg = 1000 g). Imperial conversions include 1 pound ≈ 0.453592 kg, 1 ounce ≈ 0.0283495 kg.
Volume: The base unit is the liter (L). Metric conversions are straightforward (1 L = 1000 mL). Imperial conversions use approximations like 1 US gallon ≈ 3.78541 liters, 1 US fluid ounce ≈ 0.0295735 liters.
When you select 'From Unit' and 'To Unit', the calculator identifies the correct conversion path. If both units belong to the same category (e.g., meters to kilometers), it applies the direct metric conversion. If one is metric and the other imperial, it uses the established conversion factors to bridge the gap via the base unit.
Example Usage:
Scenario 1: Converting Kilometers to Miles
If you input 10 for 'Value', select 'Kilometer (km)' for 'From Unit', and 'Mile (mi)' for 'To Unit':
1. The calculator converts 10 km to meters: 10 km * 1000 m/km = 10,000 m.
2. It then converts meters to miles: 10,000 m / 1609.34 m/mile ≈ 6.21 miles.
Result: 10 Kilometers is approximately 6.21 Miles.
Scenario 2: Converting Pounds to Kilograms
If you input 150 for 'Value', select 'Pound (lb)' for 'From Unit', and 'Kilogram (kg)' for 'To Unit':
1. The calculator converts 150 lb to kilograms: 150 lb * 0.453592 kg/lb ≈ 68.04 kg.
Result: 150 Pounds is approximately 68.04 Kilograms.
Scenario 3: Converting Liters to US Gallons
If you input 20 for 'Value', select 'Liter (L)' for 'From Unit', and 'US Gallon (gal)' for 'To Unit':
1. The calculator converts 20 L to US Gallons: 20 L / 3.78541 L/gal ≈ 5.28 US Gallons.
Result: 20 Liters is approximately 5.28 US Gallons.
Why Use This Calculator?
This tool is invaluable for students, professionals, travelers, and anyone who encounters measurements in different systems. It ensures accuracy and saves time by eliminating the need for manual calculations or searching for conversion charts.
function convertUnit() {
var valueInput = document.getElementById("value");
var fromUnit = document.getElementById("fromUnit").value;
var toUnit = document.getElementById("toUnit").value;
var resultDiv = document.getElementById("result");
var value = parseFloat(valueInput.value);
if (isNaN(value)) {
resultDiv.innerHTML = "Please enter a valid number.";
return;
}
var conversionFactors = {
// Length (Base: Meter)
"meter": 1,
"kilometer": 1000,
"centimeter": 0.01,
"millimeter": 0.001,
"mile": 1609.34,
"yard": 0.9144,
"foot": 0.3048,
"inch": 0.0254,
// Mass (Base: Kilogram)
"kilogram": 1,
"gram": 0.001,
"milligram": 0.000001,
"tonne": 1000,
"pound": 0.453592,
"ounce": 0.0283495,
// Volume (Base: Liter)
"liter": 1,
"milliliter": 0.001,
"cubic meter": 1000,
"us gallon": 3.78541,
"us quart": 0.946353,
"us pint": 0.473176,
"us cup": 0.24, // Approximation
"us fluid ounce": 0.0295735
};
var baseUnitValue = 0;
var resultValue = 0;
// Determine the category of units to ensure valid conversions
var lengthUnits = ["meter", "kilometer", "centimeter", "millimeter", "mile", "yard", "foot", "inch"];
var massUnits = ["kilogram", "gram", "milligram", "tonne", "pound", "ounce"];
var volumeUnits = ["liter", "milliliter", "cubic meter", "us gallon", "us quart", "us pint", "us cup", "us fluid ounce"];
var fromCategory = "";
var toCategory = "";
if (lengthUnits.includes(fromUnit)) fromCategory = "length";
if (massUnits.includes(fromUnit)) fromCategory = "mass";
if (volumeUnits.includes(fromUnit)) fromCategory = "volume";
if (lengthUnits.includes(toUnit)) toCategory = "length";
if (massUnits.includes(toUnit)) toCategory = "mass";
if (volumeUnits.includes(toUnit)) toCategory = "volume";
if (fromCategory !== toCategory || fromCategory === "") {
resultDiv.innerHTML = "Cannot convert between different categories (e.g., Length to Mass).";
return;
}
// Convert to base unit
if (fromCategory === "length") {
baseUnitValue = value * conversionFactors[fromUnit];
} else if (fromCategory === "mass") {
baseUnitValue = value * conversionFactors[fromUnit];
} else if (fromCategory === "volume") {
baseUnitValue = value * conversionFactors[fromUnit];
}
// Convert from base unit to target unit
if (fromCategory === "length") {
resultValue = baseUnitValue / conversionFactors[toUnit];
} else if (fromCategory === "mass") {
resultValue = baseUnitValue / conversionFactors[toUnit];
} else if (fromCategory === "volume") {
resultValue = baseUnitValue / conversionFactors[toUnit];
}
// Format the result to a reasonable number of decimal places
var formattedResult = resultValue.toFixed(4);
// Remove trailing zeros if they are after the decimal point
formattedResult = formattedResult.replace(/\.0+$/, "").replace(/(\.\d)0+$/, "$1″);
// Remove decimal point if the number becomes an integer after removing trailing zeros
if (formattedResult.endsWith('.')) {
formattedResult = formattedResult.slice(0, -1);
}
resultDiv.innerHTML = value + " " + document.getElementById("fromUnit").options[document.getElementById("fromUnit").selectedIndex].text + " is approximately " + formattedResult + " " + document.getElementById("toUnit").options[document.getElementById("toUnit").selectedIndex].text;
}