🔄

Conversion Calculators

Free unit converters for length, area, volume, weight, temperature, and more. Instant conversions between metric, imperial, and US units.

1 calculator
Advertisementslot: cat-top

Unit conversion is one of those tasks where being approximately right isn't good enough — you need exact factors. The converters on this page use the official defined conversions (1 inch = 2.54 cm exactly, 1 lbf = 4.4482216152605 N, 1 cubic foot = 28.3168465592 L), not the rounded approximations you find in school textbooks that introduce 1–2% error.

Each converter handles multiple units in both directions: type a value in any field and the others update instantly. Behind the scenes, calculations route through a SI base unit (meters, newtons, etc.) so the relationships between any two units are consistent. If you need to verify a conversion, the source factors are documented on each calculator's page.

Available unit converters

💪

Force Converter

Convert between newton, pound-force, kilogram-force, dyne, kip, poundal, and 9 other force units instantly with exact conversion factors.

Unit converters — frequently asked questions

How do you convert between metric and imperial units?
Multiply by the exact conversion factor. 1 inch = 2.54 cm (defined, not measured), 1 mile = 1609.344 m, 1 pound = 0.45359237 kg, 1 gallon (US) = 3.785411784 L. Our converters do this automatically, but if you ever check by hand: don't use 2.5 cm/inch or 1.6 km/mile — those introduce small but real errors that compound over multiple conversions.
What is the difference between mass and force?
Mass is how much matter something contains (measured in kilograms, pounds-mass, or slugs); force is what gravity (or any acceleration) does to that mass (measured in newtons, pound-force, or kilogram-force). A 1 kg mass experiences about 9.807 N of weight on Earth. The pound is ambiguous in everyday speech but precise in physics: pound-mass (lbm) is a unit of mass, pound-force (lbf) is a unit of force.
Why is 1 newton equal to 0.224809 pound-force?
Because 1 N is defined as the force required to accelerate 1 kg at 1 m/s², while 1 lbf is the force gravity exerts on 1 lbm at standard gravity (9.80665 m/s²). Crunching the numbers: 1 lbf = 0.45359237 kg × 9.80665 m/s² = 4.4482216152605 N exactly. The inverse gives 1 N = 0.22480894... lbf.
What is a kilogram-force?
A kilogram-force (kgf) is the force that standard Earth gravity exerts on a 1 kg mass: exactly 9.80665 N. It's an older "gravitational" unit that's still used in some engineering contexts (especially in continental Europe), but SI prefers the newton because it doesn't depend on a gravity value. 1 kgf ≈ 2.205 lbf.