About Units Converter

Units Converter exists to make accurate measurement conversion universally accessible. Every day, millions of people — from middle-school students working on homework to NASA engineers calculating spacecraft trajectories — need reliable, fast unit conversions. Our mission is to provide the most comprehensive, scientifically rigorous, and intuitive unit conversion platform on the web.

Unlike calculator apps that hard-code approximate values, every conversion factor on Units Converter is derived from primary sources: the U.S. National Institute of Standards and Technology (NIST Special Publication 811), the International Bureau of Weights and Measures (BIPM SI Brochure, 9th edition), the 1959 International Yard and Pound Agreement, and the IEEE 1541-2002 standard for binary multiples. We carry 8 significant figures internally and round only at display, ensuring scientific-grade accuracy at every step.

Units Converter follows the international hierarchy of measurement authorities. When sources disagree, we cite the more authoritative reference and explain the difference. Our primary sources include:

• BIPM (Bureau International des Poids et Mesures) — the international authority for SI base units and the definitions of the kilogram, meter, second, ampere, kelvin, mole, and candela.
• NIST SP 811 — the U.S. National Institute of Standards and Technology guide for the use of the International System of Units, the definitive English-language reference for SI in the United States.
• 1959 International Yard and Pound Agreement — the treaty that fixed the inch at exactly 25.4 mm and the pound at 0.45359237 kg, governing all U.S. and U.K. customary unit conversions.
• IEC 60027-2 / IEEE 1541 — international standards for the binary multiples used in digital storage (KiB, MiB, GiB) versus decimal multiples (KB, MB, GB).
• IUPAC — for chemistry-related units like the mole, atomic mass unit, and electronvolt.

Units Converter is used by professionals and learners across every continent. Our visitors include high-school and university students learning physics, chemistry, and engineering; teachers preparing lessons; civil and mechanical engineers verifying drawings; nurses and pharmacists computing dosages; chefs scaling recipes between metric and imperial; pilots calculating fuel and altitude; and software developers handling unit-aware data.

The site is fully translated into the language of measurement: every unit is presented with its scientific definition, common abbreviation, plural form, regional usage, and relationship to other units. Our goal is that no one — whether converting square feet to square meters for a real-estate listing or converting electronvolts to joules for a particle-physics calculation — has to leave Units Converter to find what they need.

Start with the most common conversions, browse the complete encyclopedia, or use the search bar to jump directly to any unit pair.