Unit Converter
Convert length, weight, volume, area, speed & data.
100% private — runs in your browser, nothing is uploaded.
1 Millimetre (mm) = 0.001 Metre (m)
How to use the Unit Converter
- 1Choose a category
Pick length, weight, volume, area, speed or digital storage.
- 2Enter a value
Type the amount you want to convert into the From field.
- 3Select the units
Choose the unit you are converting from and the unit you want to convert to.
- 4Read and copy
The converted value appears instantly — copy it with one click.
Examples
| Input | Output |
|---|---|
1 mile → kilometres | 1.609344 km |
5 kg → pounds | 11.0231 lb |
1 GB → megabytes | 1024 MB |
Free online unit converter
This unit converter handles the measurements you meet every day — length, weight, volume, area, speed and digital storage — in a single tool. Switch category, pick your units, and the result updates instantly.
What you can convert
- Length: millimetres, centimetres, metres, kilometres, inches, feet, yards, miles.
- Weight: milligrams, grams, kilograms, tonnes, ounces, pounds, stone.
- Volume: millilitres, litres, cubic metres, and US cups, pints and gallons.
- Area: square cm, square metres, hectares, square km, square feet, acres.
- Speed: m/s, km/h, mph and knots.
- Data: bytes, KB, MB, GB and TB (binary).
How it works
Every unit is expressed as a ratio to a single base unit for its category. To convert, the tool turns your input into base units and then into the target unit — a simple, accurate method. Because it all runs in your browser, conversions are instant, private and available offline.
Frequently Asked Questions
What units can I convert?
This tool covers length (mm to miles), weight/mass (mg to stone), volume (ml to gallons), area (cm² to acres), speed (m/s to mph) and digital storage (bytes to terabytes). Pick a category, then choose the from and to units.
How accurate are the conversions?
Each unit is defined by its exact ratio to an SI base unit, so conversions are precise to several significant figures — more than enough for everyday and most technical use.
Does it use US or imperial gallons?
The volume units use US customary measures (US gallon, cup, pint, teaspoon and tablespoon). US and imperial gallons differ, so check which one your recipe or spec means.
Are digital storage units in binary or decimal?
The storage category uses binary (1 KB = 1024 bytes), which matches how operating systems usually report file and disk sizes.
Is my data uploaded anywhere?
No. Every conversion is calculated in your browser with JavaScript, so nothing you type is sent to a server. It also works offline.
Can I copy the result?
Yes. Use the copy button next to the result to copy the full-precision converted value to your clipboard.
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