Roof Replacement Cost Calculator
Estimate roof replacement costs using size, material, pitch, tear-off, and decking repair.
Roof replacement estimates should account for roof area, not just the home footprint. Pitch, valleys, penetrations, tear-off layers, and damaged decking can all move the final quote.
How this estimate is calculated
The planning formula uses this model: roof area = footprint x pitch area multiplier; total = roof area x material installed rate x local and complexity multipliers + tear-off + decking repair + contingency.The output is shown as a low, typical, and high range so you can compare assumptions instead of treating one number as a quote.
Planning notes
- If you know the actual roof square count, use that to sanity-check the footprint-based estimate.
- Steep roofs, multi-story homes, chimneys, skylights, and many valleys increase labor and safety requirements.
- Storm damage, structural repairs, gutters, fascia, and insurance claim scope are not included in this simple estimate.
Factors that change the price
- Roof area and pitch
- Material choice
- Number of old layers to remove
- Decking condition
- Flashing, ventilation, skylights, and access
DIY vs hiring a pro
DIY can reduce labor cost for simple, low-risk work, but the savings disappear when a project needs permits, structural changes, licensed trades, waterproofing, gas, electrical, roof access, or specialized tools. Use the calculator to understand the scope, then ask contractors to explain which assumptions are included in their bids.
Frequently asked questions
Why is roof area larger than home square footage?
The roof surface follows the slope. Overhangs, garages, porches, and pitch usually make roof area larger than the building footprint.
Should I add contingency to a roof estimate?
Yes. Hidden decking damage, code updates, ventilation changes, and weather-related scheduling can add cost after tear-off begins.