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R-30 vs R-38 Insulation Calculator (Florida)
Compare R-30 and R-38 attic insulation for your Florida home side by side — cost, depth, and long-term savings.
Total conditioned square footage (from your listing or tax record).
R-30
R-38
RecommendedFor Central Florida, R-38 is the recommended attic standard — the small added cost over R-30 pays back through year-round cooling savings and better comfort.
Estimates are for planning only and based on typical Central Florida homes and 2026 pricing for blown-in fiberglass. Your exact price depends on attic access, existing insulation condition, and whether removal is needed — confirmed free during your inspection.
R-30 and R-38 are the two levels most Florida homeowners weigh. R-30 is an older minimum; R-38 is the current recommended standard for Florida attics. The jump from R-30 to R-38 is only a few extra inches of material — but in Florida's climate that extra resistance keeps working every cooling season.
This tool shows both options side by side for your specific home so you can see the real cost difference and decide whether the upgrade to R-38 is worth it (for almost every Central Florida home, it is).
What goes into this estimate
R-30. About 12 inches of blown-in fiberglass. Meets older code minimums but leaves savings on the table in Florida's heat.
R-38. About 15 inches — the current Florida standard and Florida Attics' recommendation for the best comfort and cooling savings.
Cost difference. Usually modest — the crew is already on site, so you're mostly paying for a few extra bags of material.
Savings difference. R-38 captures noticeably more cooling savings over the life of the insulation.
Frequently asked questions
Is R-38 better than R-30 in Florida?
Yes. R-38 is the recommended standard for Florida attics. The extra few inches over R-30 cost relatively little when you're already insulating and deliver more cooling savings every year.
What's the difference between R-30 and R-38?
R-value measures resistance to heat flow — higher is better. R-38 is about 15 inches of blown-in fiberglass versus about 12 inches for R-30, giving roughly 25% more insulating power.
Should I pay extra for R-38?
In Florida, almost always. The marginal cost over R-30 is small and the added comfort and cooling savings make R-38 the better long-term value.
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