Water Heater Blanket Calculator
A blanket on an older tank pays for itself in a season. Enter your tank size for blanket dimensions, cost and expected savings.
Your project
Your results
- Blanket size needed
- 5.2 ft × 5 ft
- Surface area
- 26 sq ft
- Recommended R-value
- R-10
- Estimated annual savings
- $19
- Typical blanket cost
- $38
- Payback period
- 2 years
Estimates use typical US material and labor pricing. Confirm quantities against the coverage chart on the bag before you buy.
Gear for this job
Water Heater Insulation Blanket
Frost King SP57/11C All Season Water Heater Insulation Blanket, 3” Thick x 48” x 75”, R10
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AES Industries Water Heater Blanket Jacket Insulation Non Fiberglass Fits 40 50 60 and 80 Gallon Tank R8
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76"x48" Water Heater Insulation Blanket for 40-80 Gallon Pre-Oxidized Fiber | Soft tight fit, easy cut & install, includes 25.5" round top spacer & 16FT foil tape for complete installation
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Pipe Insulation Foam
Duck Brand Foam Pipe Covers, Pipe Insulation Foam Tubes for Hot and Cold Water Pipes, Pre Slit and Self Sealing Adhesive Edge, 0.75 in. x 1 Ft., 6 Sticks Per Package, 6 Feet Total, Black
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CARGEN 1/2" ID Foam Pipe Insulation Fits 1/2" OD Copper & PEX Water Pipes | For 1/2" OD PEX, PE, copper & water lines; 3/8" wall x 6FT, helps protect against freezing and condensation
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Pipe Insulation Tubing (1-1/2" x 3/8" x 6FT), 1-1/2" ID Pipe Insulation Foam Tubing, Guitar Stand Foam Tubing, Hollow Tube Covers, Gym Handle Protectors and Roof Racks, Etc.
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Foil Tape Hvac Insulation
Romeda Aluminum Foil Tape, 2 inch x 65 Feet Foil Tape (3.9 mil), Silver Insulation Adhesive Metal Tape, High Temperature Heavy Duty HVAC Tapes for Ductwork, Dryer Vent, HVAC
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Aluminum Foil Duct Tape Heavy Duty Waterproof, Premium Silver Metal HVAC Heat Tapes (2"*65Feet,3.9mil), High Temperature, Dryer Vent Insulation Tape for Ductwork, Ducting, Sealing, Patching, Furnace
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ETERART Aluminum Foil Duct Tape, High-Temp Seal for HVAC,2" x 20Yds | Heavy-Duty, Dryer Vents & Insulation, Stops Air Leaks & Resists Extreme Heat for Home Repair, Silver, easy to apply, durable
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How this calculator works
- Blanket width = π × tank diameter
- Surface area = circumference × tank height
- Savings ≈ water heating share of the bill × 3–5%
Frequently asked questions
Can you put a blanket on a gas water heater?
Yes, but never cover the top, the burner access, the thermostat, the pressure relief valve or the flue. Electric tanks can be wrapped everywhere except the controls.
Do new water heaters need a blanket?
Usually not — anything made in the last decade already has R-16 or better foam. Touch the side of the tank: if it feels warm, a blanket helps.
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Blanket size needed
5.2 ft × 5 ft