OneEquals is a free set of unit converters and printable charts, built by a small team in Bulgaria.
We built it for the everyday questions: how many grams in an ounce, what 350 °F is in Celsius, which ring size to order, how long 170 cm is in feet. Every page gives the answer first, shows the exact formula, and comes with a chart you can print or save as a PDF.
How we keep the numbers right
Every conversion is calculated from the official definitions published by NIST and the International Bureau of Weights and Measures, not copied from other sites. See How we calculate for the definitions and rounding rules.
Found a mistake? Email hello@oneequals.com and we’ll fix it.