Biot Number Calculator
Compute the Biot number Bi = h·L/k for heat transfer.
Input Data
Heat Transfer Coefficient
W/(m²·K)
Char Length
m
Thermal Conductivity
W/(m·K)
Results
Bi = h·L/k.
0.3333
At a glance:Bi = h·L_c/k; Bi ≪ 1 means uniform internal temperature (lumped). Complements fourier-number and thermal-conductivity.
Formula
Bi = h·L_c / k.
$$\mathrm{Bi} = \dfrac{h\,L_c}{k_{\text{solid}}}$$How to Use
- Enter h, L and k.
- The tool returns the Biot number.
Case Studies
h=10, L=0.05, k=200
Bi = 0.0025 (lumped ok).
FAQ
Bi < 0.1?
Use the lumped-capacitance method (uniform temperature).
Related Tools
References
Content review: Calculatorism Editorial Team. Results are for reference only; please refer to the relevant authorities for the official figures.