What does thermal conductivity mean?

Thermal conductivity (λ or k) describes how quickly heat flows through a material. High λ (like copper at 401 W/(m·K)) means heat passes easily - good for heat sinks. Low λ (like mineral wool at 0.04 W/(m·K)) means heat is blocked - good for insulation. Heat flux = λ × (ΔT / thickness).

What are the most common unit systems for thermal conductivity?

Engineering uses W/(m·K) globally (SI). US HVAC and building codes often use BTU/(h·ft·°F) or BTU·in/(h·ft²·°F). Chemical engineering texts may use cal/(s·cm·°C) or kcal/(h·m·°C). 1 BTU/(h·ft·°F) ≈ 1.7307 W/(m·K).

Is my data sent anywhere?

No. All calculations run in your browser using JavaScript.

/ developer tools

Thermal Conductivity Converter

Live

From

Sig. figures:

Sci notation

Watt per metre·Kelvin

W/(m·K)

1(input)

Watt per metre·°C

W/(m·°C)

Milliwatt per metre·Kelvin

mW/(m·K)

1000

Kilowatt per metre·Kelvin

kW/(m·K)

0.001

Watt per centimetre·Kelvin

W/(cm·K)

0.01

BTU·in per hour·ft²·°F

BTU·in/(h·ft²·°F)

6.93347

BTU per hour·ft·°F

BTU/(h·ft·°F)

0.577789

BTU per second·ft·°F

BTU/(s·ft·°F)

0.000160497

Calorie per second·cm·°C

cal/(s·cm·°C)

0.00239006

Kilocalorie per hour·m·°C

kcal/(h·m·°C)

0.860421

Kilocalorie per hour·cm·°C

kcal/(h·cm·°C)

0.00860421

Privacy First: Your files are processed securely. Whenever possible, processing happens in your browser and files are never stored on our servers.

Convert thermal conductivity (λ) across SI, BTU, and caloric units. 11 units including W/(m·K), mW/(m·K), kW/(m·K), W/(cm·K), BTU/(h·ft·°F), BTU·in/(h·ft²·°F), BTU/(s·ft·°F), cal/(s·cm·°C), kcal/(h·m·°C). Reference: Cu 401, Al 237, steel 50, air 0.026 W/(m·K). 100% browser-based.

How to Use

1Type a thermal conductivity value (e.g. 1 for W/(m·K))
2Select your starting unit from the From dropdown
3Select your target unit - the result appears instantly
4All conversions appear across SI, BTU, and Caloric groups simultaneously
5Hover any row to copy or use as input; click ⇄ to swap
6Open 'Material thermal conductivity reference' for common material values

Features

11 thermal conductivity units across SI, BTU, and Caloric groups
Covers W/(m·K), BTU/(h·ft·°F), BTU·in/(h·ft²·°F), cal/(s·cm·°C), kcal/(h·m·°C)
Material reference: Cu, Al, steel, glass, water, air, mineral wool
Adjustable significant figures and scientific notation toggle
One-click copy per result
100% browser-based

Thermal Conductivity Converter

How to Use

Features

Frequently Asked Questions

/ related tools

Community Feedback

Reviews

Rate & Review

/ share this tool