A unit converter turns one measurement into another using a fixed published definition. Every tool below runs
entirely in your browser: type a value and the answer appears immediately, with no account, no download and no
page reload. Each page also shows the formula behind the result, a quick-reference chart and answers to the
questions people ask most, so you can check the number rather than just trust it.
Weight and mass converters
Weight conversion is the busiest family on CalcPilot. A kilogram equals 2.2046226218 pounds, a pound equals exactly 0.45359237 kilograms, and a stone equals 6.35029318 kilograms or 14 pounds. People land here with three different habits: metric users converting body weight or a shipping carton into pounds, US users reading a label in kilograms, and UK users who still think in stones. The kg to lbs converter handles every one of those directions and shows both readings from a single value.
Length and distance converters
Length conversions rest on exact definitions: one inch is 2.54 centimetres, one international foot is 0.3048 metres, and one mile is 1.609344 kilometres. Because those numbers are fixed, results never drift. The length converter covers millimetres, centimetres, metres, kilometres, inches, feet, yards and miles in one bidirectional tool, which is usually faster than hunting for a single-pair page. Area follows the same definitions squared — one square foot is 0.09290304 square metres — so land measurements use their own converter.
Volume and capacity converters
Volume is where US and UK customary units diverge most, and picking the wrong one produces a real error. A US liquid gallon is 3.785411784 litres, while an imperial gallon is about 4.546 litres — roughly 20% larger. The volume converter uses US customary units throughout, covers litres, millilitres, cubic metres, US gallons, quarts, cups, fluid ounces and cubic feet, and states that convention on the page so recipe and fuel calculations stay honest.
- liter and volume converter — L, mL, m³, US gal, qt, cup, fl oz, ft³
- speed converter — m/s, km/h, mph, knots, ft/s
Temperature converters
Temperature is the one everyday conversion that is not a simple multiplication, because Celsius and Fahrenheit have different zero points as well as different degree sizes. The formula is °F = °C × 9/5 + 32, and the reverse is °C = (°F − 32) × 5/9. Water freezes at 0 °C / 32 °F and boils at 100 °C / 212 °F; the two scales only agree at −40. Weather forecasts, oven settings and body temperature are the three cases where people need this most, and all three reference points are listed on the page.
Data storage converters
Storage sizes have two competing conventions. Operating systems use binary multiples, where 1 GB equals 1,024 MB, while drive manufacturers and network specs use decimal multiples, where 1 GB equals 1,000 MB. That gap is the whole explanation for a “500 GB” drive reporting about 465 GB of usable space. The converters below use binary units and say so explicitly, and each page also explains the decimal alternative. The full chain divides by 1,024 at every step: 1,024 KB to a MB, 1,024 MB to a GB, 1,024 GB to a TB.
Time and duration converters
Time runs on a base-60 system inherited from Babylonian mathematics: 60 seconds to a minute, 60 minutes to an hour, 24 hours to a day. The time converter moves between hours, minutes, seconds and days instantly, which is the fastest way to answer questions like how many minutes are in a working week or how many seconds are in a day. For calendar arithmetic rather than durations — days between two dates, or your exact age — the date tools handle the leap years for you.
