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Both calculators run independently — change the inputs on either side to compare results.

LMTD Heat Exchanger Calculator

Compute the log mean temperature difference (LMTD) — the effective driving force for heat transfer in a heat exchanger, given the four end-of-fluid temperatures. The standard input to the design equation Q = U·A·LMTD for sizing or rating exchangers.

Hot Fluid Inlet Temperature (°C)

Hot Fluid Outlet Temperature (°C)

Cold Fluid Inlet Temperature (°C)

Cold Fluid Outlet Temperature (°C)

Chemical Engineering

Pipe Pressure Drop Calculator

Compute the friction term f·(L/D)·(v²/2) from the Darcy-Weisbach equation — the specific energy loss per unit mass of fluid flowing through a straight pipe. Multiply by fluid density to get pressure drop in Pa, or divide by g for head loss in metres.

Friction Factor

Pipe Length (m)

Pipe Diameter (m)

Fluid Velocity (m/s)

Key differences

	LMTD Heat Exchanger Calculator	Pipe Pressure Drop Calculator
Category	Chemical Engineering	Chemical Engineering
Inputs required	4	4
Result	LMTD (°C)	Pressure Drop (m)
What it does	Compute the log mean temperature difference (LMTD) — the effective driving force for heat transfer in a heat exchanger, given the four end-of-fluid temperatures. The standard input to the design equation Q = U·A·LMTD for sizing or rating exchangers.	Compute the friction term f·(L/D)·(v²/2) from the Darcy-Weisbach equation — the specific energy loss per unit mass of fluid flowing through a straight pipe. Multiply by fluid density to get pressure drop in Pa, or divide by g for head loss in metres.