Unit converter
Metric ↔ imperial for everyday life: cm to inches, kg to lbs, °C to °F, km to miles, L/100 km to mpg and more — with exact factors.
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Popular conversions
- All units
- cm to inches
- inches to cm
- metres to feet
- feet to metres
- km to miles
- miles to km
- kg to lbs
- lbs to kg
- grams to ounces
- ounces to grams
- Celsius to Fahrenheit
- Fahrenheit to Celsius
- litres to US gallons
- US gallons to litres
- ml to US fl oz
- US fl oz to ml
- cups to ml
- km/h to mph
- mph to km/h
- sq ft to sq m
- sq m to sq ft
- MB to GB
- GB to MB
- mpg to L/100 km
- L/100 km to mpg
- PSI to kPa
- Calories to kJ
Exact conversion factors
All factors use international definitions: 1 inch = 2.54 cm, 1 foot = 0.3048 m, 1 mile = 1609.344 m, 1 pound = 0.45359237 kg and 1 US gallon = 3.785411784 L. Results are calculated from those, not from rounded tables.
US vs imperial units
Canada is officially metric, but recipes, tire pressures and real-estate listings often use US or imperial units. Gallons and fluid ounces differ between the two systems: a US gallon is 3.785 L and an imperial (UK) gallon is 4.546 L. The converter lists both.
Data: MB vs MiB
Storage makers and phone plans use decimal units (1 GB = 1000 MB). Windows and many apps measure in binary units (1 GiB = 1024 MiB), which is why a “1 TB” drive shows about 931 GB. Pick the right one above.
Converting money instead? Use the currency converter. For body measurements, the BMI calculator takes both metric and imperial.
Frequently asked questions
How many centimetres are in an inch?
Exactly 2.54 cm. The inch has been defined that way since 1959.
How do I convert kg to lbs?
Multiply kilograms by 2.20462. For example, 23 kg × 2.20462 ≈ 50.7 lb.
What’s the formula for Celsius to Fahrenheit?
°F = °C × 9/5 + 32. So 20 °C is 68 °F and 37 °C is 98.6 °F.
Are these US or imperial gallons?
Both are available. “Gallons (US)” is 3.785 L and “Gallons (UK)” is 4.546 L.
Why does my 1 TB drive show less space?
The drive is sold in decimal terabytes, but your computer reports binary tebibytes. 1 TB = 0.909 TiB, so you see about 931 GB.