Imperial / Metric Converter
Length, area, volume, weight, temperature and pressure
Inputs
Results
Enter a value then click Convert.
NAIBC / IRC codes
References & Sources
Standards Cited
- NIST Special Publication 811 — Guide for the Use of the International System of Units (SI)
Authoritative source for all imperial-to-metric conversion factors used in this calculator View → - ASTM E621 — ASTM E621 — Standard Practice for the Use of Metric (SI) Units in Building Design and Construction
Provides guidance on metric conversions for North American construction applications - NIST Handbook 44 — Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices
Legal definitions of US customary units and their metric equivalents View →
Formulas Used
- Generic Unit Conversion:
result = value x (fromFactor / toFactor)
Source: NIST SP 811 — All conversions route through an SI base unit (metres, kilograms, etc.) - Celsius to Fahrenheit:
F = (C x 9/5) + 32
Source: NIST SP 811 - Fahrenheit to Celsius:
C = (F - 32) x 5/9
Source: NIST SP 811 - Celsius to Kelvin:
K = C + 273.15
Source: SI Brochure
Key Assumptions
- 1 inch = 0.0254 m exactly — NIST Special Publication 811
- 1 US gallon = 0.00378541 m³ (3.78541 litres) — NIST Special Publication 811
- 1 US short ton = 907.185 kg — NIST Special Publication 811
- 1 US hundredweight = 45.3592 kg (100 lb) — NIST Special Publication 811
- Pressure conversion: 1 psi = 6894.76 Pa — NIST Special Publication 811