Pipe Insulation Calculator

Insulation thickness from pipe diameter and temperature.

Inputs

Pipe diameter (nominal)

Pipe length

Fluid temperature

°F

Ambient temperature

°F

Insulation thickness

Insulation material

Tab to move between fields

Results

Heat loss (insulated)

1,544 BTU/hr

Est. annual savings

$305.00

≈ 6 tanks of gas

Heat loss (bare pipe)6,627 BTU/hr

Heat loss reduction76.71%

Temp drop per 100 ft1.5 °F

Insulation R-value4

Material cost$250.00

R Value4

How to Use This Calculator

Enter Pipe diameter (nominal), Pipe length, and Fluid temperature.
Set Ambient temperature, Insulation thickness, and 0.5.
Adjust 1, 1.5 as needed.
Review Heat loss (insulated) (BTU/hr) and Est. annual savings ($).
Use Heat loss (bare pipe) (BTU/hr) and Heat loss reduction (%) to inform your decision.

How the result changes with Fluid temperature

Fluid temperature	Heat loss (insulated)	Est. annual savings
79	288 BTU/hr	$57.00
196	2,696 BTU/hr	$533.00
336	5,578 BTU/hr	$1,102.00
453	7,986 BTU/hr	$1,578.00

What each input means

Pipe diameter (nominal): Nominal pipe size in inches (e.g. 0.75, 1, 1.5, 2, 4).
Pipe length: Total length of pipe run to insulate.
Fluid temperature: Temperature of fluid inside the pipe (hot water, steam, chilled water).
Ambient temperature: Temperature of surrounding air.
Insulation thickness: Thickness of pipe insulation. ASHRAE 90.1 specifies minimum by pipe size and temperature.
Insulation material: Insulation material. Lower k-value means better thermal resistance.

What each result means

Heat loss (insulated): Total heat loss with insulation installed.
Heat loss (bare pipe): Heat loss without any insulation.
Heat loss reduction: Percentage decrease in heat loss from insulation.
Temp drop per 100 ft: Temperature drop of fluid per 100 ft at 2 GPM flow.
Insulation R-value: Thermal resistance of the insulation layer.
Material cost: Estimated cost of pipe insulation material.
Est. annual savings: Annual energy cost savings vs bare pipe (gas at $1.20/therm).

How this is calculated

Worked example, using the default values

Identify Input Parameters
4 parameters
Pipe diameter (nominal) = 2, Pipe length = 100, Fluid temperature = 140, Ambient temperature = 65 = 6 input(s) provided
Calculate Heat loss
Heat loss = heatLossPerFt * pipeLength
1544 = 1544
Calculate Est. annual savings
Est. annual savings = (annualBtuSaved / 100000 / 0.80) * 1.20
305 = $305
Calculate Heat loss
Heat loss = heatLossBarePerFt * pipeLength
6627 = 6627
Calculate Heat loss reduction
Heat loss reduction = round((heatSaved / max(1
76.71 = 76.71%

Engine last updated July 28, 2026.

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