Ans

Unit converters

Exact conversions, with the definition in view.

Metric, imperial, US customary and scientific units, converted through one stated base unit. Every page says whether its values are exact definitions or conventions.

Ans Convert138free converters

Converter catalogue

Everyday

Pick the quantity; the units and the common pairs are on the page.

33 unitsLength & distancecm, in, mm, ft, m and more. 25 unitsMass & weightlb, kg, st, g, oz and more. 5 unitsTemperature°F, °C, K, °R, °Ré. 34 unitsVolume & capacitymL, fl oz (US), L, gal (imp), cup (US) and more. 15 unitsAreaft², m², ac, ha, mm² and more. 12 unitsSpeedmph, km/h, kn, m/s, ft/s and more. 16 unitsTimemin, h, d, yr, s and more. 7 unitsFuel economympg (UK), L/100 km, mpg (US), km/L, mi/L and more.

Converter catalogue

Engineering

Pick the quantity; the units and the common pairs are on the page.

17 unitsPressurepsi, bar, kPa, atm, Pa and more. 17 unitsEnergykcal, kJ, J, cal, kW·h and more. 13 unitsPowerhp, kW, PS, W, BTU/h and more. 10 unitsForceN, kN, dyn, kgf, lbf and more. 7 unitsTorqueN·m, N·cm, kN·m, lbf·ft, lbf·in and more. 8 unitsVolumetric flowm³/s, L/s, L/min, m³/h, gal (US)/min and more. 5 unitsMass flowkg/s, g/s, kg/h, t/h, lb/h. 5 unitsAccelerationm/s², g₀, ft/s², Gal, km/h/s. 7 unitsFrequencyHz, kHz, MHz, GHz, THz and more. 4 unitsAngular velocityrad/s, °/s, rpm, rps.

Converter catalogue

Digital & electrical

Pick the quantity; the units and the common pairs are on the page.

19 unitsDigital storageMB, GB, TB, B, bit and more. 7 unitsData transfer rateMbit/s, MB/s, bit/s, kbit/s, Gbit/s and more. 4 unitsElectric chargeC, mC, A·h, mA·h.

Converter catalogue

Science & materials

Pick the quantity; the units and the common pairs are on the page.

10 unitsAngle°, rad, mrad, gon, ′ and more. 10 unitsDensitykg/m³, g/cm³, g/mL, kg/L, g/L and more. 3 unitsIlluminancelx, fc, ph. 7 unitsRadioactivityBq, kBq, MBq, GBq, Ci and more. 5 unitsRadiation doseSv, mSv, µSv, rem, mrem. 5 unitsMagnetic flux densityT, mT, µT, G, kG. 4 unitsDynamic viscosityPa·s, P, cP, lbf·s/ft². 3 unitsKinematic viscositym²/s, St, cSt. 4 unitsAmount of substancemol, mmol, µmol, kmol. 4 unitsAmount concentrationmol/m³, mol/L, mmol/L, µmol/L. 6 unitsSpecific energyJ/kg, kJ/kg, cal/g, kcal/kg, BTU/lb and more. 2 unitsThermal conductivityW/(m·K), BTU/(h·ft·°F). 4 unitsEV efficiencyWh/km, Wh/mi, kWh/100 km, mi/kWh.

Same name, different unit

A pint is not a pint.

US and imperial volumes are named separately; decimal and binary data prefixes stay distinct; force is not mass; energy is not torque; and reciprocal economy units are never treated as ordinary multipliers.

From the maker of Ans — a scientific calculator you can own. Same idea: a proper instrument, nothing in the way.