Unit converter
Two-way conversion across 11 categories — length, area, volume, mass, temperature, speed, pressure, energy, power, data storage and time — with configurable precision, the exact formula and handy reference values.
Runs in your browserEvery computation happens in your browser — your data never leaves this device.
Result
Formula: ft = m × 3.28084
| Input (m) | ft |
|---|---|
| 1 | 3.2808 |
| 10 | 32.8084 |
| 100 | 328.084 |
| 1000 | 3280.8399 |
All units in this category
| Unit | Symbol | Value |
|---|---|---|
| Nanometer (nm) | nm | 1000000000 |
| Micrometer (µm) | µm | 1000000 |
| Millimeter (mm) | mm | 1000 |
| Centimeter (cm) | cm | 100 |
| Meter (m) | m | 1 |
| Kilometer (km) | km | 0.001 |
| Inch (in) | in | 39.3701 |
| Foot (ft) | ft | 3.2808 |
| Yard (yd) | yd | 1.0936 |
| Mile (mi) | mi | 0.0006 |
| Nautical mile (nmi) | nmi | 0.0005 |
| Li (Chinese mile) (li) | li | 0.002 |
What this tool does
- Convert units while cooking, shopping abroad or reading specs: how many kilometres is a mile, what 100 °F is in °C, how many jin is a pound.
- See every unit in a category at once — 12 lengths, 10 data units, 10 time units — instead of flipping the dropdown back and forth.
- Confirm exact factors before writing code or docs: the page shows the formula “target = source × factor + offset” so you can copy it straight into a program.
- Sanity-check typical values: each category ships reference points (temperature uses −40, 0, 37, 100, 212) so a suspicious result is obvious.
Example
Input
Category: Length From: Mile (mi) To: Kilometer (km) Value: 1
Output
Result: 1.6093 Formula: km = mi × 1.609344
The factor in the formula is the exact definition (1 mile = 1609.344 metres), while the displayed result is rounded to the “decimals” setting, 4 by default — set it to 6 and you see 1.609344.
Frequently asked questions
Why is 100 °F shown as 37.7778 °C and not 37.8?
Results are rounded to the configured number of decimals, 4 by default. Temperature uses an affine conversion with an offset, shown as °C = °F × 0.555556 + -17.777778. Lower the decimals setting for fewer digits or raise it for more.
What is the difference between MB and MiB?
MB is 1000-based (10^6 bytes) and MiB is 1024-based (2^20 bytes). Drive vendors usually quote the former and operating systems report the latter, which is why a “1 TB” drive shows about 931 GiB. Both are listed so you can keep them apart.
Can I convert across categories, say metres to seconds?
No — a cross-category conversion fails on purpose, because length and time have no conversion factor between them. The dropdown only lists units of the selected category, and switching category picks that category’s first two units automatically.
How are Chinese units such as li, jin and mu defined?
Using the mainland market standard: 1 li = 500 m, 1 jin = 0.5 kg, 1 liang = 50 g and 1 mu = 2000/3 m² (about 666.67 m²). These are the current PRC definitions; Taiwan and Hong Kong differ.
Where do Mach, the speed of light and the year come from?
Mach uses 340.29 m/s, the standard sea-level speed of sound; the speed of light is the exact 299792458 m/s; a year is 365.25 days (Julian) and a month is fixed at 30 days. These units are conventions, so check that yours match before relying on them.
Keywords：单位换算unit converter长度面积体积质量温度速度压力能量功率数据存储时间