Unit Converter

1. Choose a category such as Length, Weight & mass or Temperature.
2. Type a value. You can use decimals, thousands separators (1,234.5), scientific notation (1.5e3) or fractions (5 3/8).
3. Pick the units in the From and To menus. Use the swap button to reverse them.
4. Read the result and tap Copy result to copy the number.
5. Explore. All units converts your value into every unit in the category at once. Table shows common values side by side.

Your last-used units are remembered on this device only, and the page URL updates so you can bookmark or share a conversion.

• Length: kilometres, metres, centimetres, miles, yards, feet, inches, nautical miles, light years and more.
• Weight & mass: kilograms, grams, pounds, ounces, stone, tonnes, US and UK tons, carats.
• Temperature: Celsius, Fahrenheit, Kelvin and Rankine.
• Volume: litres, millilitres, US and imperial gallons, pints, cups, fluid ounces, tablespoons, teaspoons, cubic units.
• Area: square metres, hectares, acres, square feet, square miles and more.
• Speed: m/s, km/h, mph, knots, feet per second, Mach and the speed of light.
• Time: nanoseconds to centuries.
• Data storage: bits, bytes, decimal (kB, MB, GB) and binary (KiB, MiB, GiB) units.
• Pressure: pascals, bar, atmospheres, psi, mmHg, inHg.

How do I convert Celsius to Fahrenheit?

Multiply the Celsius value by 9/5 and add 32. For example, 100 °C × 9/5 + 32 = 212 °F. To go back, subtract 32 and multiply by 5/9.

What is the difference between a US gallon and an imperial gallon?

A US gallon is 3.785 litres and an imperial (UK) gallon is 4.546 litres, so an imperial gallon is about 20% larger. The same applies to quarts, pints and fluid ounces, so pick the right one for your recipe or fuel figures.

Is a kilobyte 1000 or 1024 bytes?

Both are used. The SI prefixes kB, MB and GB mean powers of 1000. The binary prefixes KiB, MiB and GiB mean powers of 1024. Storage makers usually advertise decimal units, while operating systems often show binary ones, which is why a "1 TB" drive shows about 931 GiB.

How accurate are the conversions?

Factors for metric and international units are exact definitions, for example 1 inch = 2.54 cm and 1 pound = 0.45359237 kg. Results are calculated with standard double-precision numbers. Decimals are rounded to the number of significant digits you choose (6 by default), and the whole-number part is never rounded away.

How many days are in a month or a year here?

A year is 365.25 days and a month is the average Gregorian month (30.4369 days), so month and year results are averages, not calendar-specific.

Can I type fractions?

Yes. Enter values like 3/8 or 5 3/8. When you convert to inches or feet, the result also shows a fraction (to the nearest 1/16 by default, adjustable under More options).

Is my data private?

Yes. All conversions run in your browser and nothing you type is sent to a server. Your last-used units are stored only on your device.