19 / unit-converter
free online tool
Unit Converter
Convert between length, weight, temperature, and more — instantly.
how to use
- 01
Select a category (e.g. Length, Weight, Temperature).
- 02
Enter a value and choose the source unit.
- 03
The converted values in all other units appear instantly.
about
What is this tool?
Unit Converter covers the most commonly used unit conversion categories: length (m, km, mi, ft, in), weight (kg, g, lb, oz), temperature (°C, °F, K), volume (L, mL, gal), and area (m², ft², acre). All calculations are performed locally using precise conversion factors.
why use this tool
- -Save time on manual conversions.
- -Covers everyday and scientific units.
- -Accurate to many decimal places.
- -No internet connection required after page load.
features
- -Length: metre, kilometre, mile, foot, inch, centimetre.
- -Weight: kilogram, gram, pound, ounce.
- -Temperature: Celsius, Fahrenheit, Kelvin.
- -Volume and area conversions.
comparison
Metric vs Imperial: Quick Reference
| Metric | Imperial Equivalent | Category | Exact? |
|---|---|---|---|
| 1 kilometre | 0.621 miles | Length | Yes |
| 1 kilogram | 2.205 pounds | Weight | Yes |
| 0°C | 32°F | Temperature | Yes (offset formula) |
| 1 litre | 0.264 US gallons | Volume | Yes |
| 1 metre² | 10.764 feet² | Area | Yes |
All processing happens entirely in your browser using JavaScript. No files, text, or data are ever sent to a server. Your data stays on your device.
✦ tip from dragontail
Living in Korea and working with global clients means I convert between metric and imperial constantly — especially for screen sizes (inches vs centimetres) and app store screenshot dimensions. One conversion I've memorised: 1 inch = 2.54 cm exactly. Everything else I look up, and this tool is my first stop.
faq
How accurate are the conversions?
Conversions use precise factors (e.g. 1 inch = 2.54 cm exactly). Floating-point precision may cause minor rounding in the last decimal place.
Can I convert between metric and imperial?
Yes. Metric ↔ imperial conversions are fully supported for all categories.
Is temperature conversion linear?
No. Temperature requires an offset formula. For example: °F = (°C × 9/5) + 32.