One converter for everything — length, weight, volume, temperature, time and data units.
Exact factors throughout: 1 inch = 2.54 cm, 1 lb = 0.45359237 kg, 1 US gallon = 3.785411784 litres, and data units use 1024 (so 1 MB = 1024 KB). Temperature uses the exact Celsius / Fahrenheit / Kelvin relations.
Converted result
How to use this tool
Length, weight, volume, temperature, time or data — each category has its own units and exact factors.
Type the number, choose “From” and “To”. Every unit in the category is listed underneath, so you see all conversions at once.
The chart below the result lists the classic equivalents — 1 mile = 1.609344 km, 1 US gallon = 3.785411784 litres, -40 °C = -40 °F — for quick checking.
“Swap units” reverses the direction instantly; “Copy result” copies the answer for a document or message.
Formula & worked example
Worked examples: 5 miles to km: 5 × 1609.344 ÷ 1000 = 8.04672 km. 100 °F to °C: (100 − 32) × 5/9 = 37.7778 °C. 2 GB to MB: 2 × 1073741824 ÷ 1048576 = 2048 MB. 1 US gallon to litres: 3.785411784 litres.
Limitations — read this before you rely on it
Volume units here are US customary (cup, pint, quart, gallon); UK imperial units differ (1 imperial gallon = 4.54609 litres), so check which gallon a recipe means. The “year” is the Julian year of 365.25 days, an average — a specific calendar year is 365 or 366 days. Data “KB/MB” here means 1024-based units; storage makers sometimes label 1000-based sizes with the same letters.
Frequently asked questions
A tool that converts a number from one unit to another — length, weight, volume, temperature, time or data — using exact factors, so you do not have to look up tables.
Multiply miles by 1.609344. For example, 10 miles = 16.09344 km. Or pick Length here and convert directly.
The two scales cross at -40: -40 °C × 9/5 + 32 = -40 °F. It is the only temperature where the numbers match.
Both conventions exist. This converter uses 1024 (the operating-system convention), so 1 MB = 1024 KB and 2 GB = 2048 MB.
A US gallon is 3.785411784 litres; an imperial (UK) gallon is 4.54609 litres. This converter uses US gallons — check which one your source means.