Conversion Calculators
Convert physical units and number bases with exact internationally defined factors — 1 inch = 25.4 mm exactly, 1 mile = 1.609344 km. Includes length, weight, temperature, volume, and binary/octal/decimal/hexadecimal conversion with the working shown.
What can you convert with these tools?
The Unit Converter handles physical measurements — length, weight, temperature, volume, area and speed — using exact internationally defined factors (the inch has been exactly 25.4 mm since 1959; one pound is exactly 0.45359237 kg). The Number Converter translates values between decimal, binary, octal and hexadecimal, the number bases used throughout computing.
Why do exact conversion factors matter?
Because rounded factors compound. Converting a 42.195 km marathon with the rough factor 1.6 gives 26.37 miles, while the exact factor 1.609344 gives the correct 26.219 miles — a difference of nearly a quarter mile. Both converters use full-precision definitions and only round the displayed result.
Frequently asked questions
One mile is exactly 1.609344 kilometers — a definition fixed by international agreement in 1959. Going the other way, one kilometer is about 0.621371 miles. So a 10 km run is roughly 6.21 miles.
Multiply each binary digit by its power of two and add the results. For 1011: 1×8 + 0×4 + 1×2 + 1×1 = 11 in decimal. The Number Converter shows this positional breakdown for any base.
Multiply by 9/5 and add 32: °F = °C × 1.8 + 32. So 25 °C is 77 °F, and body temperature of 37 °C is 98.6 °F. Temperature is the one common conversion that needs an offset, not just a multiplier.