Seven categories in one place, because the alternative is a different tab for every conversion and a nagging doubt about whether the site used US or imperial gallons.
What the Unit Converter does
Converts within Length, Mass, Area, Volume, Speed, Data and Time, plus Temperature, which is handled separately because it does not scale from zero.
Everything except temperature is a simple ratio against a base unit, which is why the conversions are exact rather than rounded lookups.
Open the Unit Converter and follow the settings and checks below.
What is covered
| Setting | What it means |
|---|---|
| Length | mm, cm, m, km, in, ft, yd, mi, nautical miles |
| Mass | mg, g, kg, tonne, oz, lb, stone |
| Volume | mL, L, m³, tsp, tbsp, cup, pint, quart, gallon |
| Speed | m/s, km/h, mph, knots, ft/s |
| Data | B, KB, MB, GB, TB — binary, so 1 KB = 1024 B |
| Time | ms, s, min, h, day, week |
| Temperature | C, F, K — converted by formula, not ratio |
How to use it
- Pick a category.
- Choose the units to convert from and to.
- Type the value — the result updates as you type.
Practical advice
The volume units are US customary. A US gallon is about 3.785 litres and an imperial gallon is about 4.546, a difference of 20% — which is enough to ruin a recipe or badly mislead a fuel-economy comparison. Check which one your source meant before trusting the number.
Common questions
Is 1 KB 1000 or 1024 bytes?
Here it is 1024, the binary convention operating systems use. Storage manufacturers use 1000, which is why a "500 GB" drive shows as roughly 465 GB in your file manager. Neither is wrong; they are different definitions, and the gap grows with size.
Why is temperature separate?
Because it has no true zero to scale from. Every other conversion is multiplication by a ratio, but Celsius to Fahrenheit needs an offset as well as a factor — 0°C is 32°F, not 0°F, so a simple ratio gives nonsense.
Are these US or imperial gallons?
US. The two differ by about 20%, along with pints and quarts. If your source is British, the numbers will not match, and on fuel economy the error is large enough to matter.
How precise are the results?
The factors are the standard exact definitions — an inch is exactly 0.0254 m, a mile exactly 1609.344 m. Precision is limited by ordinary floating-point arithmetic, which is far beyond anything you would notice.
Useful next tools
- Length Converter — Convert miles, km, feet, inches, metres and more.
- Weight Converter — Convert kg, pounds, ounces, stone and grams.
- Temperature Converter — Convert Celsius, Fahrenheit and Kelvin.
- Data Size Converter — Convert bytes, KB, MB, GB, TB and bits.
- Speed Converter — Convert mph, km/h, m/s, knots and ft/s.
- Volume Converter — Convert litres, gallons, cups, pints and millilitres.
Vootkit provides a browser calculator and educational guidance. Results depend on the values and units you enter, so verify important financial, academic, safety or professional decisions with an appropriate authoritative source.
Try the tools from this guide
Keep reading
How to Generate a Barcode That Works
Generates a scannable barcode in CODE128, EAN-13, UPC-A or CODE39 from whatever value you enter.
How to Create an Accurate Countdown for Any Event
Counts down to any date and time you pick, updating every second, in days, hours, minutes and seconds.
How to Generate Random Numbers for Draws and Tests
Generates numbers in a range you set, one or many, with an option to make every result unique.