Thermal conductivity measures how well a material conducts heat: copper about 400 W/(m·K), glass about 1, insulation foam 0.03. Fourier’s law turns it into a heat flow through walls, pans and electronics.
How to use the Thermal Conductivity Calculator
- Find
- Material
- Thermal conductivity k
- Measured heat flux
- Temperature difference ΔT
- Thickness Δx
- Area (optional)
Results update as you type, every field has its own unit menu, and everything is calculated in your browser.
How it works
Choose what to find and enter the values.
Tips
- Use absolute temperature (K) in gas laws and efficiency formulas.
- Temperature differences are the same in K and °C.
- Heat = mass × specific heat × temperature change when no phase change occurs.
- Phase changes need latent heat at a constant temperature.
Common mistakes to avoid
- Using °C in pV = nRT.
- Forgetting latent heat during melting or boiling.
- Confusing heat capacity (J/K) with specific heat (J/(kg·K)).
Inputs explained
| Field | What to enter |
|---|---|
| Find | Choose one: Heat flux, Thermal conductivity |
| Material | Choose one: Copper, Aluminium, Carbon steel, Stainless steel … |
| Thermal conductivity k | Units: W/(m·K), BTU/(h·ft·°F) |
| Measured heat flux | Units: W/m², kW/m² |
| Temperature difference ΔT | Units: K, °C, °F |
| Thickness Δx | Units: cm, mm, m, in, ft |
| Area (optional) | Units: m², cm², mm², km², in², ft² |
Example values
How the main result changes when Thermal conductivity k changes and everything else stays at the example values above:
| Thermal conductivity k (W/(m·K)) | Heat flux q″ (W/m²) |
|---|---|
| 0.5 | 144 |
| 0.75 | 144 |
| 1 | 144 |
| 1.25 | 144 |
| 1.5 | 144 |
| 2 | 144 |
Formula
q″ = k·ΔT/Δx, Q̇ = q″·AWorked example
Inputs — Find: Heat flux; Material: Brick; Temperature difference ΔT: 20 K; Thickness Δx: 10 cm; Area (optional): 1 m².
Results — Heat flux q″ = 144 W/m²; Heat flow = 144 W.
Key terms
- Heat flux
- Heat flow per unit area.
Frequently asked questions
Which material conducts heat best?
Diamond (~2,000 W/(m·K)), then silver and copper.
Why are gases good insulators?
Their molecules are far apart.
What is Fourier's law?
Heat flux is proportional to the temperature gradient.
Why do foams insulate well?
They trap still air in tiny cells.
What formula does the Thermal Conductivity Calculator use?
q″ = k·ΔT/Δx, Q̇ = q″·A.