Unit Converter
Length, weight, temperature, area, volume, speed and data. Runs in your browser.
About this unit converter
This unit converter changes values between metric, imperial and US customary units across eight categories: length, weight, temperature, area, volume, speed, time and data size. Type one number and you see it in every unit of that category at once, not just one pair.
Conversion factors use exact legal definitions where they exist, such as 1 inch = 2.54 cm and 1 pound = 0.45359237 kg. Temperature uses proper offset formulas, and data size lists both decimal units (GB) and binary units (GiB) so the 1000 vs 1024 question is answered side by side.
Results update as you type, you choose how many significant digits to show, and you can copy any value in one click. It all runs in your browser.
Features
Every unit at once
One input converts to all units in the category, so you can compare meters, feet, inches and miles without switching menus.
Eight categories
Length, weight, temperature, area, volume, speed, time and data, covering metric, imperial and US customary units.
Exact definitions
Uses the official definitions: 1 in = 0.0254 m, 1 lb = 0.45359237 kg, 1 US gallon = 231 cubic inches, 1 imperial gallon = 4.54609 L.
Correct temperature math
Celsius, Fahrenheit, Kelvin and Rankine convert with offsets, and values below absolute zero are flagged.
SI and binary data units
kB, MB, GB, TB and PB use 1000. KiB, MiB, GiB, TiB and PiB use 1024. Bits, kilobits, megabits and gigabits are included for network speeds.
Adjustable precision
Show 4, 6, 8, 10 or 12 significant digits. Tiny and huge results switch to scientific notation so they stay readable.
Swap and copy
Swap the from and to units with one button, click any row to make it the main result, and copy any value as a plain number.
How to use the unit converter
- 1Pick a category.
- 2Enter a value and choose its unit.
- 3See every unit at once. Click a row to make it the main result.
When to use it
Cooking and recipes
Convert cups, tablespoons and fluid ounces to milliliters, and see US and imperial measures side by side.
Travel
Turn km/h into mph, kilometers into miles, or a Celsius forecast into Fahrenheit.
Buying storage
See why a 1 TB drive shows about 931 GiB in your operating system.
Homework and science
Convert between nanometers and meters, or Kelvin and Celsius, with enough digits for lab work.
Home and property
Convert square feet to square meters, or acres to hectares, when comparing listings.
Metric vs imperial vs US customary
The metric system (SI) is built on powers of 10. A kilometer is 1000 meters and a milliliter is a thousandth of a liter. Most of the world uses it for everyday measurements.
The imperial system, still used for some things in the UK, and the US customary system share many unit names but not always the same sizes. Lengths and weights match: an inch, foot, mile, ounce and pound are the same in both. Volumes do not.
- US gallon: 3.785411784 liters. Imperial gallon: 4.54609 liters.
- US fluid ounce: about 29.57 mL. Imperial fluid ounce: about 28.41 mL.
- US pint: 16 US fl oz. Imperial pint: 20 imperial fl oz.
- US (short) ton: 2,000 lb. UK (long) ton: 2,240 lb. Metric ton: 1,000 kg.
Why temperature conversion is different
Most units convert by multiplying by a fixed factor. Temperature scales also have different zero points, so they need an offset. Fahrenheit = Celsius × 9/5 + 32, and Kelvin = Celsius + 273.15.
Because of the offset, a reading and a difference convert differently. A temperature of 10 °C is 50 °F, but a rise of 10 °C is a rise of 18 °F. This tool converts readings. Nothing can be colder than absolute zero (0 K, −273.15 °C or −459.67 °F), so values below it are marked.
KB vs KiB: 1000 or 1024?
Storage makers use decimal units: 1 GB is 1,000,000,000 bytes. Operating systems such as Windows count in binary, where 1 GiB is 1,073,741,824 bytes, but often label the result GB.
That is why a 1 TB drive appears as about 931 GB on a computer. Nothing is missing. It is the same number of bytes counted in a different unit. Network speeds use bits, not bytes, so a 100 Mbit/s connection moves at most 12.5 MB per second.
Why use Mavros
| Mavros | Typical upload sites | |
|---|---|---|
| Output | Every unit in the category at once | One from and one to unit at a time |
| Data units | Decimal and binary units side by side | Often only one, unlabeled |
| Precision | Choose 4 to 12 significant digits | Fixed rounding or long float noise |
| Speed | Live results as you type | Convert button or page reload |
| Ads | None in the way of the results | Ads around the converter |
| Privacy | Runs in your browser | Requests sent to a server |
Tips
- Click a row in the full list to make it the highlighted result at the top.
- Use Swap to reverse a conversion without retyping the value.
- Pick 4 significant digits for everyday use and 10 or 12 for engineering work.
- For recipes, check whether the source is American or British before converting cups, pints or gallons.
- Copy gives a plain number without thousands separators, which pastes cleanly into spreadsheets.
Questions
How many centimeters are in an inch?
Exactly 2.54. The inch has been defined as 0.0254 meters since 1959.
How do I convert kilograms to pounds?
Divide kilograms by 0.45359237, or multiply by about 2.20462. Select Weight, enter the value in kilograms and read the pound row.
How do I convert Celsius to Fahrenheit?
Multiply by 9/5 and add 32. 25 °C is 77 °F. The converter applies this formula for you, and works the other way too.
Are data units 1000 or 1024 based?
Both are listed. KB, MB and GB use 1000 (decimal). KiB, MiB and GiB use 1024 (binary).
Why does my 1 TB drive show less space?
Drive makers count in decimal terabytes, but most operating systems count in binary units. 1 TB is about 931 GiB, which the system may label as GB.
Is a US gallon the same as a UK gallon?
No. A US gallon is 3.785 liters and an imperial (UK) gallon is 4.546 liters. Both are in the volume list.
How do I convert km/h to mph?
Divide by 1.609344. 100 km/h is about 62.14 mph. Select Speed to see all speed units at once.
How long is a month or a year in this converter?
Both use the Gregorian calendar average: a year is 365.2425 days and a month is one twelfth of that.
Does the converter work offline?
Yes, once the page has loaded. All conversions run in your browser and nothing is sent to a server.