# Insulation R-Value Calculator

> Insulation R-value calculator: total R-value for layered walls, attic, or floor assemblies from thickness and material. Free, runs locally, no signup.

- **Canonical URL:** https://boringtoolskit.com/insulation-calculator/
- **Category:** Construction & Measurement
- **Evidence level:** catalogue
- **Reviewed:** July 26, 2026
- **Last verified:** 2026-10-12
- **Privacy:** Inputs and results stay in this browser unless the page clearly labels an external request.

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*Local planning estimate. Verify current terms, rates, and policies before acting.*