Unit Converter

How to Use the Unit Converter

Select a category from the tabs (Length, Weight, Temperature, etc.). Enter a value in any unit — all other units in the category update instantly.

Unit Converter Formula

Example Calculation

Metric vs Imperial: Knowing Which You Need

Most of the world, India included, runs on the metric system — metres, kilograms, litres, Celsius. The United States and a handful of others use imperial units — feet, pounds, gallons, Fahrenheit. Conversion friction shows up constantly: a product listed in inches, a recipe in Fahrenheit, a treadmill in miles, a flat-screen measured diagonally in inches while the room is in feet. This tool covers length, weight, temperature, area, volume, and speed so you do not have to memorise the multipliers.

The Conversions People Look Up Most

• Length: 1 inch = 2.54 cm, 1 foot = 30.48 cm, 1 mile = 1.609 km, 1 metre = 3.28 feet.
• Weight: 1 kg = 2.205 pounds, 1 pound = 453.6 g, 1 ounce = 28.35 g.
• Temperature: °F = (°C × 9/5) + 32; °C = (°F − 32) × 5/9.
• Volume: 1 US gallon = 3.785 litres, 1 litre = 1000 mL.
• Speed: 1 mph = 1.609 km/h; to go from km/h to m/s, divide by 3.6.

Temperature is the one that catches people out, because it is not a simple multiplication — there is an offset of 32 degrees. The quick mental version: double the Celsius and add 30 for a rough Fahrenheit (close enough for weather, not for cooking).

Why Unit Mistakes Are Expensive

Unit confusion is not a trivial nuisance — it has caused real disasters. NASA lost the $125 million Mars Climate Orbiter in 1999 because one team used metric units and another used imperial. In everyday life the stakes are lower but the annoyance is real: medicine dosed in the wrong units, a part ordered in inches that was meant to be centimetres, a recipe ruined by an oven set in the wrong scale. When a conversion matters, double-check it rather than trusting a mental estimate — the offset in temperature and the difference between US and imperial gallons are common sources of error.

A Note on US vs UK Units

Imperial is not one system. A US gallon (3.785 L) is noticeably smaller than a UK imperial gallon (4.546 L), and US and UK fluid ounces differ too. This matters most with volume — recipes, fuel economy, and fluid measurements. Length and weight are largely shared (an inch and a pound are the same on both sides of the Atlantic), so the divergence is mainly in liquids. When a source is British, assume imperial gallons; when American, assume US. This converter uses the US conventions by default, which match the majority of online content.

Frequently Asked Questions