Methodology & sources

Unitversal uses official reference factors, not values approximated from memory.

Length, weight, and volume units

Based on the International System of Units (SI) and conversion factors published by the BIPM (International Bureau of Weights and Measures). Example: 1 inch = 2.54 cm exactly (1959 international agreement).

Densities (cooking conversions)

Densities used for gram-to-milliliter conversions come from standard food reference tables (including Ciqual) and apply at roughly 20 °C. Real-world values can vary slightly by product.

Accuracy over time

This page is updated whenever an underlying factor changes. For safety-critical or professional use, we recommend checking the value against a calibrated reference.

Data units

Decimal definitions from IEC standard 80000-13: the kilobyte is 10³ bytes, the megabyte 10⁶, the gigabyte 10⁹. The binary prefixes kibi, mebi and gibi, which are powers of 1024, carry their own symbols Ki, Mi and Gi. A drive sold as 1 TB really does hold 10¹² bytes; if it shows 931 GB, that is the system dividing by 2⁴⁰ while keeping the decimal label.

Public sources

• BIPM, brochure du SI Definitions of the base units and of the units accepted for use with the SI.
• NIST, Special Publication 811 Guide for the use of the SI, with exact conversion factors to customary units.
• ANSES, table Ciqual Food densities used by the cooking conversions.