Methodology: how we build and check our tools
Every UnitPilot tool follows the same process so you can trust the answer — and check it yourself.
1. Recognized formulas and sources
Formulas come from published, widely accepted sources. The main ones used on this site are:
- Exact conversion factors from the 1959 international yard and pound agreement (1 in = 2.54 cm, 1 lb = 0.45359237 kg)
- US customary and UK imperial volume definitions
- SI and IEC prefixes for data storage (KB vs KiB)
2. Tested against worked examples
Before a tool goes live, it is run with the example inputs shown on its page and the result is compared with a hand-checked answer. Edge cases — zero, very large numbers, leap years, empty fields — are tested too, and the tool shows a clear message instead of a wrong number.
3. Shown on every page
Each page has a How it works section, the formula and a worked example, so you can repeat the calculation by hand.
4. Rounding
Calculations use full precision internally. Results are rounded only for display — money to cents, most measurements to 2–4 decimal places.
5. Limits
Tools give estimates for general information. They cannot know your full situation. For money, health, legal or tax decisions, confirm with a qualified professional.
6. Updates and corrections
Rates and tables that change (such as tax brackets) are reviewed at least once a year. If you think a result is wrong, please tell us — we check every report.