Home Maintenance Calculators
Estimate insulation quantity from area and R-value, not folklore.
Insulation projects are specified in R-value and coverage area, then converted to batts, bags of blown-in, or foam thickness. This calculator does that conversion with editable coverage and cost. It is not an energy audit, a dew-point analysis, or a recommendation to bury knob-and-tube. Air sealing often matters as much as adding R. Check local fire and ventilation rules before you close a cavity, and do not cover recessed cans that are not IC-rated.
Calculators
How to measure
Measure joist bays or wall cavities (length × width of the insulated area). Note existing insulation depth if you can see it. Attic floors are usually a rectangle minus the hatch. For walls, use net cavity area, not the whole façade including windows.
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FAQ
- Can I convert R-value to a guaranteed energy savings percent?
- Not honestly from area alone. Savings depend on climate, air leaks, and the rest of the envelope. We estimate material quantity and cost, not a utility-bill guarantee.
- Batt, blown-in, or foam?
- Batts fit standard cavities; blown-in fills irregular attics; spray foam air-seals but costs more and needs a qualified installer. Pick the product you will actually install and match its labeled R per inch.