17 categories, one converter
Each unit is stored as a factor (and, for temperature, an offset) relative to an SI base. Converting mm to inch is 0.001 m ÷ 0.0254 m; converting °C to °F uses the affine transform, not a single scale factor. Search for a unit, or pick a common pair below to pre-fill the converter.
Formula
1 in = 25.4 mm
1 lb = 0.45359237 kg
1 bar = 0.1 MPa = 14.5038 PSI
1 N·m = 0.737562 lb·ft
1 hp = 0.7457 kW (mechanical)
°F = °C × 9/5 + 32
Example — 120 MPa to PSI
Categories included
- Length (12 units, base m)
- Area (9 units, base m²)
- Volume (9 units, base m³)
- Weight / Mass (8 units, base kg)
- Temperature (4 units, base K)
- Pressure (10 units, base Pa)
- Force (5 units, base N)
- Torque (5 units, base N·m)
- Speed (5 units, base m/s)
- Time (6 units, base s)
- Power (6 units, base W)
- Energy (8 units, base J)
- Density (4 units, base kg/m³)
- Angle (5 units, base rad)
- Frequency (5 units, base Hz)
- Data (9 units, base B)
- Flow rate (5 units, base m³/s)
Common conversions
Length pairs include cm to inch, inch to cm, feet to meters, meters to feet, km to miles and miles to km. Mass is a weight converter (kg to lb, lb to kg, grams to kg, kg to tonnes, ounces to grams). Volume covers liters to gallons, gallons to liters, cubic feet to cubic meters and m³ to liters. Pressure covers MPa to PSI, PSI to MPa, bar to PSI, PSI to bar and kPa to PSI. Force covers N to kgf, kgf to N, N to lbf and lbf to N. Torque covers Nm to lb ft, lb ft to Nm, Nm to lb in and lb in to Nm. Density converter pairs live under density. CFM converter pairs are under flow rate. Click a pair to load it in the converter above.
Length
- mm to inch · 25.4 mm = 1 in
- inches to mm · 1 in = 25.4 mm
- cm to inch · 1 cm = 0.3937 in
- inch to cm · 1 in = 2.54 cm
- feet to meters · 1 ft = 0.3048 m
- meters to feet · 1 m = 3.2808 ft
- miles to km · 1 mi = 1.6093 km
- km to miles · 1 km = 0.6214 mi
Volume
- liters to gallons · 1 L = 0.2642 gal (US)
- gallons to liters · 1 gal (US) = 3.7854 L
- cubic feet to cubic meters · 1 ft³ = 0.0283 m³
- m³ to liters · 1 m³ = 1,000 L
- liters to m³ · 1,000 L = 1 m³
Weight / Mass
- kg to lb · 1 kg = 2.2046 lb
- lb to kg · 1 lb = 0.4536 kg
- grams to kg · 1,000 g = 1 kg
- kg to tonnes · 1,000 kg = 1 t
- ounces to grams · 1 oz = 28.3495 g
Temperature
- Celsius to Fahrenheit · 0 °C = 32 °F
- Fahrenheit to Celsius · 32 °F = 0 °C
Pressure
- MPa to PSI · 1 MPa = 145.0377 PSI
- PSI to MPa · 145 PSI = 0.9997 MPa
- bar to PSI · 1 bar = 14.5038 PSI
- PSI to bar · 14.5 PSI = 0.9997 bar
- kPa to PSI · 100 kPa = 14.5038 PSI
- bar to MPa · 10 bar = 1 MPa
Force
Torque
- Nm to lb ft · 1 N·m = 0.7376 lb·ft
- lb ft to Nm · 1 lb·ft = 1.3558 N·m
- Nm to lb in · 1 N·m = 8.8507 lb·in
- lb in to Nm · 1 lb·in = 0.113 N·m
Speed
- km/h to mph · 100 km/h = 62.1371 mph
- mph to km/h · 60 mph = 96.5606 km/h
- m/s to km/h · 1 m/s = 3.6 km/h
Power
Density
- g/cm³ to kg/m³ · 1 g/cm³ = 1,000 kg/m³
- kg/m³ to g/cm³ · 1,000 kg/m³ = 1 g/cm³
Angle
- degrees to radians · 180 ° = 3.1416 rad
- radians to degrees · 1 rad = 57.2958 °
Frequency
Data
- bytes to KB · 1,024 B = 1.024 kB
- MB to GB · 1,000 MB = 1 GB
- GB to MB · 1 GB = 1,000 MB
- MB to MiB · 1 MB = 0.9537 MiB
Flow rate
- L/min to L/s · 60 L/min = 1 L/s
- L/min to GPM · 1 L/min = 0.2642 gpm
- GPM to L/min · 1 gpm = 3.7854 L/min
- CFM to L/min · 1 cfm = 28.3168 L/min
Pair this with the material weight calculator when a drawing mixes millimetres and inches, the STEP model weight calculator to convert CAD mass into kg or lb, or the ISO tolerance calculator when you need micrometres from a millimetre nominal.