TL;DR — The Unit Converter handles length, weight, temperature, time, area, speed, data size, and CSS units in one place. For live exchange rates use the Currency Converter; for cooking and weather quick-conversions, the dedicated Temperature Converter.
Conversions that trip people up
- KB vs KiB. 1 KB = 1,000 bytes (SI). 1 KiB = 1,024 bytes (binary). Hard drives use KB, OS reports often use KiB — that’s why "1 TB drive" shows as ~931 GiB in Windows.
- px vs rem vs em. 1 rem = the root font size (usually 16 px). 1 em = the parent’s font size. Use rem for accessible scaling, em for component-relative sizing.
- Celsius ↔ Fahrenheit.
F = C × 9/5 + 32. Memorize: 0 °C = 32 °F, 100 °C = 212 °F, 20 °C ≈ 68 °F (room temp).
- kg ↔ lb. 1 kg ≈ 2.205 lb. 1 lb ≈ 0.454 kg.
- km ↔ mi. 1 km ≈ 0.621 mi. 1 mi ≈ 1.609 km.
Use the converter in 5 seconds
- Open the Unit Converter.
- Pick a category (length, weight, temperature, etc.).
- Type the value in any unit — every other unit updates live.
- Copy whichever output you need.
Categories supported
- Length — mm, cm, m, km, in, ft, yd, mi, nautical mi.
- Weight — mg, g, kg, t, oz, lb, st.
- Temperature — Celsius, Fahrenheit, Kelvin.
- Time — ms, s, min, h, day, week, year.
- Area — m², km², ft², acre, hectare.
- Speed — m/s, km/h, mph, knots.
- Data size — bytes through TiB, both SI and binary.
- CSS — px, rem, em, % (with configurable root size).
FAQ
Is 1 GB the same as 1 GiB?
No. 1 GB = 10⁹ bytes (1,000,000,000). 1 GiB = 2³⁰ bytes (1,073,741,824). The difference grows at larger scales — a "16 GB" SD card holds ~14.9 GiB.
What’s 1 rem in pixels?
By default, 16 px (the browser default root size). If the user has increased browser font size, 1 rem scales with it — which is why rem-based layouts are more accessible than px.
Does the converter use live currency rates?
The Unit Converter handles physical units. For live FX, use the dedicated Currency Converter.
Math toolkit