Physics

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Thermal Conductivity Calculator.

Calculate steady one-dimensional slab conductivity using Fourier conduction.

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Set your values

Results update as you type.

Thermal conductivity: 0.5 W/(m·K)

Thermal conductivity

0.500000W/(m·K)

Results update automatically as you type.

Use Cases

Material Selection for Insulation

Engineers can estimate the thermal conductivity of a material sample by measuring heat flow and temperature difference, helping choose appropriate insulation.

Example: Test a 0.05 m thick panel with 10 W heat flow across 1 m² and 20 K difference.

Educational Demonstrations

Students can verify Fourier's law and understand how thickness, area, and temperature gradient affect conduction.

Example: Compare conductivity of different materials by varying inputs.

Frequently Asked Questions

How is thermal conductivity calculated in this calculator?
This calculator uses Fourier's law for steady one-dimensional conduction: k = (Q * L) / (A * ΔT), where Q is the heat transfer rate in watts, L is the slab thickness in meters, A is the conduction area in square meters, and ΔT is the temperature difference in kelvin.
What units are used for the inputs?
The inputs are: heat transfer rate in watts (W), slab thickness in meters (m), conduction area in square meters (m²), and temperature difference in kelvin (K). The result is thermal conductivity in watts per meter-kelvin (W/(m·K)).
Can this calculator be used for non-steady or multi-dimensional heat transfer?
No, this calculator is specifically for steady one-dimensional slab conduction. It assumes constant properties and uniform temperature difference across the slab. For transient or multi-dimensional cases, more advanced methods are required.

Tips & Common Mistakes

Tips

  • Ensure all inputs are in the correct units: watts, meters, square meters, and kelvin.
  • For accurate results, measure the temperature difference across the slab, not the absolute temperatures.
  • Use consistent temperature units; kelvin and Celsius differences are equivalent, but the calculator expects kelvin.
  • Double-check that the heat transfer rate is steady and one-dimensional for the formula to apply.

Common Mistakes to Avoid

  • Using Celsius instead of kelvin for temperature difference – the calculator expects kelvin, though the numeric difference is the same.
  • Confusing area with thickness – area is the cross-sectional area perpendicular to heat flow, not the slab's surface area.
  • Forgetting to convert units (e.g., using cm for thickness instead of meters) leads to incorrect results.

Last updated: August 13, 2026