Gambrel Roof Calculator

Find the roof area, shingle squares, and rafter lengths for four gambrel styles.

Gambrel Style

Building Length

Building Width (gable end)

Eaves Overhang on Length (ft)

Lower Slope Pitch (steep)

Upper Slope Pitch (shallow)

Knee Position (% of half width run)

Wastage %

Price per Square (optional)

Currency

LIVE CALCULATION

Squares to Order

squares

+0.00 squares estimated wastage (10%)

Roof Summary

Materials

Cost Estimate

Estimated Total-

Calculation Assumptions

Gambrel / Style-

Slope Pitches-

Knee & Ridge Heights-

Area Math-

Waste Allowance-

Pricing BasisNot specified

The four gambrel styles change how the roof surface is computed. A Dutch gambrel adds triangular hip sections at each end of the ridge. An asymmetrical gambrel uses different slopes on the left and right. A dormered gambrel adds a gable dormer roof on the lower slope. All styles assume a symmetric two-slope barn profile across each side.

Gambrel Roof Calculator

Roof Summary

Materials

Cost Estimate

Calculation Assumptions

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