A free, fast unit converter that runs entirely in your browser. Convert length, weight, temperature, area, volume, speed, digital storage, and time units instantly — pick a category, choose your units, type a value, and see the result live. No signup, no uploads: every conversion happens locally on your device.
How to use this unit converter
Pick a category (Length, Weight/Mass, Temperature, Area, Volume, Speed, Digital storage, or Time), choose the unit you're converting from and the unit you're converting to, then type a value. The result updates live as you type, along with the unit rate (for example, 1 km = 0.62137119 mi). Hit the swap button to flip the direction instantly. Everything runs locally in your browser — nothing you enter is sent to a server.
Common conversions explained
- Kilometers ↔ miles: 1 mile = 1.609344 km exactly, so 1 km ≈ 0.621371 miles. A 10 km run is about 6.2 miles.
- Kilograms ↔ pounds: 1 lb = 0.45359237 kg exactly, so 1 kg ≈ 2.204623 lb. A 70 kg person weighs about 154.3 lb.
- Celsius ↔ Fahrenheit: °F = (°C × 9/5) + 32. So 0 °C = 32 °F (freezing), 100 °C = 212 °F (boiling), and body temperature 37 °C ≈ 98.6 °F.
- Liters ↔ US gallons: 1 US gallon = 3.785412 liters, so 1 liter ≈ 0.264172 gallons. Note that UK (imperial) gallons are larger — this tool uses US customary volume units.
- Digital storage: this converter uses binary (base-1024) units, matching how operating systems report file sizes: 1 KB = 1,024 bytes, 1 MB = 1,024 KB, 1 GB = 1,024 MB. Drive manufacturers use decimal (base-1000) units, which is why a "1 TB" drive shows up as about 931 GB.
Frequently asked questions
How many kilometers are in a mile?
One mile equals exactly 1.609344 kilometers, and one kilometer is about 0.621371 miles. Quick mental shortcut: multiply miles by 1.6 to get kilometers, or multiply kilometers by 0.6 to get a rough mile figure.
Is this unit converter free and private?
Yes — it's completely free, with no signup and no limits. All conversions run as JavaScript in your own browser, so the numbers you type never leave your device.
How do you convert Celsius to Fahrenheit?
Multiply the Celsius temperature by 9/5 (or 1.8) and add 32: °F = (°C × 9/5) + 32. Going the other way, subtract 32 and multiply by 5/9. Temperature is the one category where you can't just multiply by a single factor, because the scales have different zero points.
Does 1 GB equal 1000 MB or 1024 MB?
It depends on the convention. This tool uses binary (base-1024) units — 1 GB = 1,024 MB — which is how Windows and most operating systems report file and drive sizes. Storage manufacturers advertise in decimal (base-1000) units, where 1 GB = 1,000 MB, which is why an advertised "500 GB" drive appears as roughly 465 GB in your OS.
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