Thermal Converter

How these units are defined

Thermal conductivity converts between SI and US units using the International Table BTU: 1 BTU/(h·ft·°F) = 1.730735 W/(m·K).

Worked examples

• 1 W/(m·K) = 0.57778932 BTU/(hr·ft·°F)
• 10 W/(m·K) = 5.7778932 BTU/(hr·ft·°F)
• 100 W/(m·K) = 57.778932 BTU/(hr·ft·°F)

Common mistakes

• •Conductivity (k) is a property of a material. U-values and R-values describe a whole wall or panel of a given thickness, so they are different quantities.

Thermal conversions

Sources for these factors

1. Guide for the Use of the International System of Units (SP 811), Appendix B: conversion factors — NIST

Last reviewed 26 October 2026 against these sources. An automated check recomputes every factor from its definition on each build. How we check accuracy

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