Our aim
Every page on FlipUnits should help someone convert a measurement correctly and understand the answer. We would rather publish fewer, better converters than many thin pages, so each converter page explains how its units are defined and where the common mistakes are.
Unit definitions
We use the exact definitions set by the 1959 international yard and pound agreement, the UK Weights and Measures Act 1985, US customary definitions and the International System of Units (SI), as published by bodies such as the BIPM and NIST. Where a unit has more than one version, such as UK and US gallons, the different cups and tablespoons, or UK and US miles per gallon, we name the version used and offer a choice where it matters.
Rounding
Calculations use exact definitions, and rounding happens only when a result is displayed. We mark rounded figures with "≈" and exact ones with "=". Where kitchen or trade conventions round figures, such as gas mark equivalents or "1 oz = 25 g", we say so.
Estimates
Some tools depend on assumptions: cup-to-gram conversions use typical ingredient densities, the BMR calculator uses the Mifflin–St Jeor equation, and BMI ranges follow NHS guidance for adults. Each page states its assumptions and limits. The currency calculator never shows or guesses exchange rates; it works with the rate you enter.
Testing
Before each update, an automated test suite checks every converter on the site against reference values calculated with exact fractions, in both directions, and checks the calculators against worked examples. We also check that every page loads, that its converter works in a real browser and that internal links are not broken.
Use of AI writing tools
We may use AI writing tools to help draft and edit explanatory text. A person reviews and edits every draft before publication and checks figures and facts against the sources above. The AI Barn is responsible for everything published on FlipUnits, however it was drafted. We do not publish invented statistics, reviews or testimonials.
Independence and advertising
FlipUnits is funded by advertising shown through Google AdSense. Advertisers do not influence our content, and we do not accept payment for recommendations.
Corrections
If you find a mistake, email hello@theaibarn.com with the page address and what looks wrong. If a converter is wrong, we fix it and add a test for the case you reported.