Pipe surface area per length (A/L) calculator

Use bare radius for bare flux and outside-insulation radius for outside-referenced insulated flux.

Units

\mathrm{A/L} = \frac{2\pi \times r}{12}

Calculator

Enter the values you know and leave one box empty. Calculate finds the empty one, the result or any input.

Given

\mathrm{A/L} = \frac{2\pi \times 3.6}{12} \approx 1.885

Symbol	Meaning	Unit
$\mathrm{A/L}$	surface area per length	ft²/ft
$r$	radius of the area reference surface	in

Symbol	Meaning	Unit
$\mathrm{A/L}$	surface area per length	m²/m
$r$	radius of the area reference surface	m

Results are estimates for study and screening. Check the inputs, units and assumptions before you use them for design, billing or contract decisions.