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Heat Exchanger LMTD and Area Calculator

LMTD = (ΔT₁−ΔT₂)/ln(ΔT₁/ΔT₂); A = Q/(U·LMTD).

Calculates the Log Mean Temperature Difference (LMTD) for a counter-flow heat exchanger and the required heat transfer area from heat duty Q and overall heat transfer coefficient U.

Priya Venkatesan By Priya Venkatesan
Published Last reviewed 1 min read

Inputs

Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

ΔT₁=T_h_in−T_c_out; ΔT₂=T_h_out−T_c_in; LMTD=(ΔT₁−ΔT₂)/ln(ΔT₁/ΔT₂); A=Q/(U×LMTD)

In depth

Calculates the Log Mean Temperature Difference (LMTD) for a counter-flow heat exchanger and the required heat transfer area from heat duty Q and overall heat transfer coefficient U.