Unit Converter

What is Unit Converter?

A unit converter is a tool that transforms a measurement from one unit to another within the same physical quantity. Whether you need to convert kilometers to miles for a road trip, kilograms to pounds for a recipe, or Celsius to Fahrenheit for weather, unit conversion is one of the most common everyday calculations. Our converter covers six categories: length (meter, kilometer, mile, foot, inch, and more), weight (kilogram, pound, ounce, stone, ton), temperature (Celsius, Fahrenheit, Kelvin), area (square meter, acre, hectare, square foot), volume (liter, gallon, cup, fluid ounce, tablespoon), and speed (m/s, km/h, mph, knot, Mach). All conversion factors follow international standards.

How It Works

Select a category (length, weight, temperature, area, volume, or speed), choose your source and target units from the dropdowns, and enter a value. The converter instantly calculates the result using exact conversion factors. For most units, we convert through a base unit (meters for length, kilograms for weight, liters for volume, etc.) using multiplication. Temperature is special — Celsius, Fahrenheit, and Kelvin use offset formulas rather than simple ratios. A table below shows the input value converted to all other units in the category.

Formula

Linear conversion: result = value × (fromFactor / toFactor)

Temperature:
°F = (°C × 9/5) + 32
°C = (°F − 32) × 5/9
K = °C + 273.15

Formula Explained

Most unit conversions are linear — they involve multiplying by a ratio. We store each unit as a factor relative to a base unit (e.g., 1 foot = 0.3048 meters). To convert, we multiply the input by the source factor to get the base unit, then divide by the target factor. Temperature is different because the scales have different zero points, requiring addition/subtraction formulas.

Example

1 mile = 1,609.344 meters = 1.609344 kilometers = 5,280 feet 1 kilogram = 2.20462 pounds = 35.274 ounces 100°C = 212°F = 373.15 K 1 US gallon = 3.78541 liters = 128 fluid ounces

Tips & Best Practices

✓Bookmark this page for quick access — unit conversion is needed more often than you think.
✓For cooking, remember: 1 cup = 16 tablespoons = 48 teaspoons.
✓The UK gallon (4.546 L) is larger than the US gallon (3.785 L) — check which one your recipe uses.
✓Temperature tip: 28°C ≈ 82°F (comfortable room temp), 0°C = 32°F (freezing).

Common Use Cases

•Converting recipe measurements between metric and imperial
•Understanding international weather forecasts in different temperature scales
•Converting distances for travel planning
•Engineering and science unit conversions
•Comparing product specifications listed in different unit systems

Frequently Asked Questions

Multiply the Celsius temperature by 9/5 and add 32. Formula: °F = (°C × 9/5) + 32. For example, 100°C = (100 × 9/5) + 32 = 212°F. Our converter handles this automatically.

1 kilogram equals approximately 2.20462 pounds. To convert kg to lbs, multiply by 2.20462. For example, 70 kg = 70 × 2.20462 = 154.32 lbs.

1 inch equals exactly 2.54 centimeters. This is an exact definition, not an approximation. To convert inches to cm, multiply by 2.54.

Metric (SI) uses meters, kilograms, and Celsius. Imperial/US customary uses feet, pounds, and Fahrenheit. Metric is used in most countries; the US primarily uses imperial for everyday measurements.

Our converter uses exact conversion factors defined by international standards (NIST/ISO). For example, 1 inch = exactly 25.4 mm, 1 pound = exactly 0.45359237 kg. Results are accurate to at least 10 significant digits.