Roof Insulation Calculator

Roof insulation needs a clear vented or unvented strategy so the sheathing stays warm enough or has a reliable drying path. Use this as early insulation planning only; confirm local code, product data, air sealing, ventilation, and moisture control.

Default building-type estimate

  • Climate zone: 5
  • Planning target: R-60
  • R-value gap from current R-19: R-41
  • Order area with 10% waste: 1,430 sq ft
  • Estimated material cost: $3,232

Planning snapshot

  • Category: Room or assembly
  • Typical use: Cathedral ceilings, unvented rooflines, exterior roof retrofits, and roof deck upgrades.
  • Hot climate target: R-30
  • Mixed climate target: R-49
  • Cold climate target: R-60

R-value calculator · Wall assembly builder · Insulation savings estimator