About Convertitive

Convertitiveis a free online converter built around one idea: you should see the answer before you can finish scrolling. No submit buttons. No popups. No “premium plan.” Every conversion happens locally in your browser, which makes the result appear the moment you type.

Why we built this

The existing converter sites are slow, ad-heavy, and trapped in a 2010-era aesthetic. We wanted a fast, modern reference that scientists, developers, cooks, and curious people could all trust — and that worked equally well on a phone in line at the grocery store, a desktop in a lab, or a tablet in the kitchen.

Every conversion factor on this site is sourced from NIST Special Publication 811 or the BIPM SI Brochure. Factors are stored exactly per the 1959 international yard and pound agreement and the SI redefinitions of 2019 — the only source of imprecision in any result is IEEE 754 double-precision arithmetic.

How calculations work

Every unit on the site is stored with a single conversion factor to a canonical base unit (meter for length, kilogram for weight, kelvin for temperature, and so on). To convert between any two units we round-trip through the base unit. For temperature, where the zero points of the scales differ, we add an offset alongside the factor — the math is identical to the textbook formulas, just generalized.

Contact

Spotted a bad number, missing unit, or a typo? Email hello@convertitive.com. We read everything.