Unit conversion tables
The factor for all 207 conversions on the site, grouped by what is being measured. Read the answer straight off the table, or open a pair for the formula, a worked example, a reference table of common values and a converter that takes any number.
Length and distance
Convert any length or distance →Metric and US customary length. The inch is defined as exactly 2.54 cm, so every metric-to-imperial length factor below is exact rather than measured.
Weight and mass
Convert any weight →Ounces here are avoirdupois (28.35 g), the ones used for food and freight — not the troy ounce used for gold. “Ton” means the metric tonne of 1,000 kg; the US short ton has its own pages.
Volume and capacity
Convert any volume →Gallons, quarts, pints, cups and fluid ounces are US customary. Imperial (UK) measures are larger — a UK gallon is 4.546 L against the US 3.785 L — so British recipes and fuel figures will not match.
An acre is 43,560 ft² by definition and a hectare is exactly 10,000 m², which is why the acre-to-hectare factor is not a round number.
Temperature
Convert any temperature →Temperature scales do not share a zero, so these convert with a formula rather than a single factor. There is no meaningful “1 °C in °F” — one degree of change is 1.8 °F, but the reading 1 °C is 33.8 °F.
| Conversion | Formula |
|---|---|
| Celsius to Fahrenheit | °F = (°C × 9/5) + 32 |
| Celsius to Kelvin | K = °C + 273.15 |
| Fahrenheit to Celsius | °C = (°F − 32) × 5/9 |
| Fahrenheit to Kelvin | K = (°F − 32) × 5/9 + 273.15 |
| Kelvin to Celsius | °C = K − 273.15 |
| Kelvin to Fahrenheit | °F = (K − 273.15) × 9/5 + 32 |
Speed
Convert any speed →Knots are nautical miles per hour, where a nautical mile is exactly 1,852 m — longer than the statute mile used on land.
| Conversion | Factor |
|---|---|
| Feet Per Second to Meters Per Second | 1 ft/s = 0.3048 m/s |
| Feet Per Second to Miles Per Hour | 1 ft/s = 0.681818 mph |
| Kilometers Per Hour to Knots | 1 km/h = 0.539957 kn |
| Kilometers Per Hour to Meters Per Second | 1 km/h = 0.277778 m/s |
| Kilometers Per Hour to Miles Per Hour | 1 km/h = 0.621371 mph |
| Knots to Kilometers Per Hour | 1 kn = 1.852 km/h |
| Knots to Meters Per Second | 1 kn = 0.514444 m/s |
| Knots to Miles Per Hour | 1 kn = 1.1508 mph |
| Meters Per Second to Feet Per Second | 1 m/s = 3.2808 ft/s |
| Meters Per Second to Kilometers Per Hour | 1 m/s = 3.6 km/h |
| Meters Per Second to Knots | 1 m/s = 1.9438 kn |
| Meters Per Second to Miles Per Hour | 1 m/s = 2.2369 mph |
| Miles Per Hour to Feet Per Second | 1 mph = 1.4667 ft/s |
| Miles Per Hour to Kilometers Per Hour | 1 mph = 1.6093 km/h |
| Miles Per Hour to Knots | 1 mph = 0.868976 kn |
| Miles Per Hour to Meters Per Second | 1 mph = 0.44704 m/s |
Data storage
Convert any file size →KB, MB, GB and TB step by 1,000 here; the IEC units KiB, MiB, GiB and TiB step by 1,024. That gap is why a 1 TB drive shows as 931 GB in Windows.
More reference tables
The other two families of answered questions on the site, indexed the same way.