About Unitglide

Unitglide is a fast, private unit converter. Type a request in plain English, or use a dedicated converter with formulas, tables and shareable links.

How we keep results accurate

• Each unit is stored once, as an exact factor (or offset for temperature) relative to an SI base unit.
• Factors come from NIST Special Publication 811, NIST Handbook 44 Appendix C and the BIPM SI Brochure (9th edition). The inch (0.0254 m) and pound (0.45359237 kg) are exact by the 1959 international agreement.
• Conversions use double-precision arithmetic, are cleaned of floating-point noise, and are rounded only for display: 5 significant figures by default, with trailing zeros dropped so exact values stay clean (1 km = 1000 m). Choose Auto for up to 10 digits, or set decimals or significant figures yourself; defining factors in formulas and reference sheets are always shown exactly.
• Hundreds of automated tests check known reference values, round trips and edge cases on every change.

US vs imperial

US customary and British imperial units with the same name (gallon, pint, cup, fluid ounce, ton) differ in size. We label them separately and let you choose a default region.

Limitations

• Volume ↔ mass conversions (for example cups to grams) depend on the ingredient and are not offered as exact conversions.
• Results are for general information. Verify safety-critical values (medication dosing, structural loads) against an authoritative source.

Factors last reviewed: 2026-10-27.