Roof Replacement Cost: How to Build a Reliable Estimate

Measure the roof, not just the house footprint

A roof’s sloped surface is usually larger than the horizontal footprint. Record each roof plane, pitch, dormers and additions, then use a roof-area calculator or a contractor’s measurement. Keep the unit consistent throughout the estimate.

List the work that belongs in the quote

Ask whether the quote includes tear-off and disposal, underlayment, flashing, valleys, ridge details, ventilation, edge metal and cleanup. Clarify how damaged roof decking will be priced if it is discovered after removal. The same scope makes competing bids easier to compare.

Calculate a range from local rates

1. Enter the measured roof area and low and high installed rates from current local quotes.
2. Add separate allowances for removal, repairs, flashing or other work not included in the unit rate.
3. Set a contingency and compare the low and high totals with written bids for the same scope.

What the estimate cannot decide

Roof covering, access, pitch, layers, weather protection and hidden damage affect the final scope. The calculator applies your inputs; it does not inspect the roof or supply market prices. Confirm materials, warranty, schedule, payment terms and any local approval with qualified local professionals.