Convert between 100+ units across 11 categories — length, weight, temperature, area, volume, speed, time, digital storage, energy, pressure, and angle. Instant results with formula explanations and full conversion tables.
Category
Unit Converter is part of the Conversion Tools collection. If you want a broader view of similar workflows, open the Conversion Tools category page or browse all QuickTools categories.
Common next steps after this tool include Length Converter, Weight Converter and Temperature Converter.
| Category | Input | Result | Formula |
|---|---|---|---|
| Length | 1 mile | 1.60934 km | × 1.60934 |
| Length | 5 feet 10 inches | 177.8 cm | (5×30.48) + (10×2.54) |
| Weight | 70 kg | 154.32 lb | × 2.20462 |
| Temperature | 100 °C | 212 °F | (100 × 9/5) + 32 |
| Temperature | 98.6 °F | 37 °C | (98.6 − 32) × 5/9 |
| Volume | 1 gallon (US) | 3.785 litres | × 3.78541 |
| Speed | 100 km/h | 62.14 mph | ÷ 1.60934 |
| Digital | 1 GB | 1024 MB | × 1024 |
| Pressure | 1 atm | 101.325 kPa | × 101.325 |
| Energy | 1 kcal | 4.184 kJ | × 4.184 |
For all categories except temperature, conversions use a base-unit ratio system. Every unit is defined as a fixed multiplier of a chosen base unit (e.g. 1 kilometre = 1000 metres). To convert from unit A to unit B:
Temperature is handled separately because its scales use different zero points. The converter always converts via Celsius as an intermediate step, applying the exact algebraic formulas (e.g. °F = °C × 9/5 + 32).
All floating-point results are rounded to 8 significant figures using symmetric rounding to eliminate trailing noise while preserving precision for scientific use.
mm, cm, m, km, in, ft, yd, mi, nmi
mg, g, kg, t, oz, lb, stone
Celsius, Fahrenheit, Kelvin, Rankine
mm², cm², m², km², in², ft², yd², ac, ha
ml, cl, l, m³, tsp, tbsp, fl oz, cup, pt, qt, gal, ft³
m/s, km/h, mph, knot, ft/s
ns, µs, ms, s, min, h, d, wk, mo, yr
bit, B, KB, MB, GB, TB, PB, Kbit, Mbit, Gbit
J, kJ, cal, kcal, Wh, kWh, BTU, MJ
Pa, kPa, MPa, bar, mbar, psi, atm, mmHg, inHg
°, rad, grad, mrad, arcmin, arcsec, full turn
Over 100 units across 11 measurement categories — from everyday conversions like km to miles, to scientific ones like pascals to atmospheres.
Yes. All conversion factors are stored at full IEEE 754 double-precision floating-point accuracy and results are rounded to 8 significant figures, which exceeds the precision needed for most engineering and scientific calculations.
Celsius, Fahrenheit, Kelvin, and Rankine do not share the same zero point, so simple multiplication doesn't work. Each conversion uses the exact algebraic formula (e.g. °F = °C × 9⁄5 + 32) rather than a ratio.
One average month is defined as 2,629,800 seconds (365.25 days ÷ 12), which accounts for the unequal lengths of calendar months and leap years.
Binary (IEC standard) — 1 KB = 1,024 bytes, 1 MB = 1,048,576 bytes. This matches how operating systems report file sizes.
The converter handles one unit at a time. To convert 5 ft 10 in, first convert 5 ft to inches (60 in), add 10 to get 70 in, then convert 70 in to your target unit.
Convert length and distance between 20 units — mm, cm, m, km, inches, feet, yards, miles, nautical miles, fathoms, light-years, astronomical units, and more. Instant results with formula, conversion factor, and full reference table.
Convert weight and mass between 17 units — micrograms, milligrams, grams, kilograms, metric tonnes, ounces, pounds, stones, short tons, long tons, carats, troy ounces, and more. Instant results with formula and full reference table.
Convert temperature between 8 scales — Celsius, Fahrenheit, Kelvin, Rankine, Réaumur, Rømer, Newton, and Delisle. Exact algebraic formulas, live results, and a full reference table for every scale.
Convert volume between 22 units — millilitres, litres, cubic metres, US teaspoons, tablespoons, cups, pints, quarts, gallons, UK pints, UK gallons, cubic inches, cubic feet, and more. Instant results with formula and full reference table.
Format, validate, minify, or sort JSON data with configurable indentation. Instantly check for syntax errors, view node count and nesting depth — free, no sign-up required.
Generate QR codes for URLs, text, Wi-Fi credentials, vCards, and more. Customise foreground and background colour, error correction level, margin, and download as SVG or PNG — free and instant.
Calculate your Body Mass Index, healthy weight range and ideal weight using metric or imperial units.
Estimate daily calorie needs based on age, gender, height, weight and activity level using Mifflin-St Jeor, Harris-Benedict or Katch-McArdle formulas.