Created By : Vaibhavi Kumari

Reviewed By : Rajashekhar Valipishetty

Last Updated : May 17, 2023

Calculate the heat flux through an object or the thermal conductivity of a substance fast with this free Thermal Conductivity Calculator. To obtain the result in a quick period of time, you must enter the data into the required input boxes and then press the blue colour to calculate button.

Distance (Δx)
Temperature difference (ΔT)
Heat flux (q)

Thermal Conductivity Definition

Thermal conductivity is described as a material's inherent capacity to transport or conduct heat. The symbol "λ" or "k" is used to represent it. There are three methods for transferring heat. One of them is thermal conductivity. Radiation and convection are the other two mechanisms.

The rate equations can be used to quantify the heat transfer process in general. Fourier's law of heat conduction is used to create the rate equation for thermal conductivity. Heat sinks are made of materials with good thermal conductivity. The reciprocal of thermal conductivity is thermal resistance. Every material has a different potential for conducting or transferring heat.

Formula of Thermal Conductivity

The formula for calculating a material's thermal conductivity is Thermal Conductivity, λ = (QL)/(AΔT)

  • Where, λ = Thermal conductivity
  • A = Area of the surface
  • Q = Amount of heat transferred
  • L = Distance between two isothermal planes
  • ΔT = Change in temperature

Heat Flux

Heat flux is the quantity of heat energy transferred per unit area every second. Fourier's law can be used to compute the heat flux.

According to Fourier's law, the area at right angles to the gradient through which the heat flows is directly proportional to the negative gradient of temperature and the time rate of heat transfer. According to Fourier's law, the heat flux is along the lines of q = -λΔT/Δx

  • where, ΔT = temperature difference across the material
  • Δx = distance of heat transfer
  • q = heat flux
  • λ = thermal conductivity of a material

For more concepts check out to get quick answers by using this free tool.

How to find Thermal Conductivity?

The rules for calculating the thermal conductivity or heat flow of any substance are as follows. Take a look at the simple steps and see what you can come up with.

  • Step 1: Find the thermal conductivity constant, the distance between two points, and the temperature difference.
  • Step 2: Divide the temperature change by the distance travelled.
  • Step 3: Multiply the result by the thermal conductivity constant's negative value.
  • Step 4: The result is known as heat flux.

Thermal Conductivity Examples

Question 1: If one end of a 0.35 m long metal bar is placed in steam and the other end is placed in ice, calculate the thermal conductivity of the material. Given that 20x10^-3 kg of ice metals every minute, the ice's later heat is 70 cal/kg, and the metal bar's cross-section is 12x10^-4 m^2.



Length L = 0.35 m

Cross-sectional area A = 12x10^-4 m^2

Amount of heat transferred Q = 20x10^-3 x 70 x 1000 = 1400 cal

Change in temperature ΔT = 60 x 100

Thermal conductivity formula is λ = (QL)/(AΔT)

= (1400 x 0.35)/(12x10^-4 x 100 x 60)

= 490/(7.2)

= 68.05

Hence, the thermal conductivity of the metal is 68.05 cal/ms°C.

FAQs on Thermal Conductivity Calculator

1. What is the definition of heat flux?

The heat flux is the amount of heat energy transmitted per unit area every second. The heat fkux is defined by Fourier's law, which is q = -λΔT/Δx.

2. What is Thermal Conductivity, and what does it mean?

The intrinsic capacity of a substance to transfer heat is referred to as thermal conductivity. The symbol k is used to represent it. watts per metre Kelvin is the SI unit for heat flux.

3. How do you use a calculator to figure out a material's thermal conductivity?

To calculate the thermal conductivity, fill in the fields of the Heat Flux Calculator with the thermal conductivity constant, distance, and temperature differential, then press the calculate button.

4. What is the impact of temperature on thermal conductivity?

The electrical conductivity of pure metals diminishes as the temperature rises. Metals' thermal conductivity does not change much as the temperature rises.

5. What factors influence thermal conductivity?

A material's thermal conductivity is strongly influenced by a variety of factors. These factors include the temperature gradient, material characteristics, and the length of the heat channel.