About HowToConvert

I built HowToConvert to make everyday measurement conversions instant, free and reliable. Whether you are cooking from a metric recipe, comparing fuel economy across regions, or sizing a hard drive, you should be able to trust the answer without second-guessing it.

The tools are deliberately clean so the converter you came for loads quickly and works on any device. There is no sign-up, and every calculation runs in your browser, so the values you type are never sent anywhere.

The converters are not guesswork. Each one is built on internationally defined relationships, for example, one inch is exactly 2.54 cm and one pound is exactly 0.45359237 kg. Every value is referenced to its SI base unit (meter, kilogram, second, kelvin) so results stay consistent across every unit pair.

Conversions that involve scales rather than simple factors, such as temperature, or fuel economy where units are inversely related, use the correct formulas, not approximations. Factors are taken from the defining standard rather than copied from another converter, and the formula is printed on each conversion page so you can check the result without trusting the tool.

These are the publications the factors are checked against:

• NIST SP 811, Appendix B: conversion factors
• NIST Handbook 44, Appendix C: general tables of units of measurement
• BIPM, The International System of Units (SI Brochure)
• NIST, Prefixes for binary multiples (IEC 80000-13)

I am Piero Nanni, and HowToConvert is an independent project I build and maintain on my own. There is no team and no editorial committee: I write the content, check the factors and ship the code.

That is worth saying plainly, because it tells you where to direct a correction and who is accountable for a wrong number. Every conversion page and guide carries a byline and the date it was last checked, and the contact page reaches me directly.

Spotted a value that looks wrong, or need a unit the site does not yet support? Corrections are genuinely welcome. Get in touch via the contact page and I will reply.