Thermal Resistance Calculator Formula

Understand the math behind the thermal resistance calculator. Each variable explained with a worked example.

Formulas Used

Thermal Resistance

thermal_resistance = thickness / conductivity

Variables

VariableDescriptionDefault
thicknessMaterial Thickness(m)0.1
conductivityThermal Conductivity(W/(m·K))0.04

How It Works

Thermal Resistance

Thermal resistance quantifies how well a material layer resists heat flow.

Formula

R = d / k

where d is thickness and k is thermal conductivity. Higher R means better insulation. For multiple layers, R-values add in series.

Worked Example

10 cm of fiberglass insulation (k = 0.04 W/(m·K)).

thickness = 0.1conductivity = 0.04
  1. 01R = d / k
  2. 02R = 0.1 / 0.04
  3. 03R = 2.5 m²·K/W

Ready to run the numbers?

Open Thermal Resistance Calculator