Roof Estimator
Pick your roof shape, enter the footprint and pitch, and see the roof area, every edge length, and a complete material list update live. One tool from shape to shopping list.
Dimensions
Roof Area
1,342 sq ft
Roofing Squares
13.4
Footprint
1,200 sq ft
Ridge Height
7.5 ft
Edge Lengths (linear ft)
- Eaves80.0
- Rakes67.1
- Ridges40.0
- Hips—
- Valleys—
| Material | Qty | Unit |
|---|---|---|
Architectural field shingles 4 bundles/square × 13.4 squares + 10% waste | 60 | bundles |
Hip & ridge cap Along 40 lf of ridges + hips (~25 lf/bundle) | 2 | bundles |
Starter strip Along 147 lf of eaves + rakes (~100 lf/bundle) | 2 | bundles |
Synthetic underlayment 1000 sq ft/roll, +10% overlap | 2 | rolls |
Drip edge Along 147 lf of eaves + rakes | 15 | 10 ft pieces |
Ice & water shield 240 sq ft band (eaves/valleys), 200 sq ft/roll | 2 | rolls |
Roofing nails ~4,723 nails (320/square), 7,200/box | 1 | coil boxes |
💡 Edge lengths are derived from your dimensions assuming equal pitch on all planes. Complex roofs (dormers, multiple wings) add valleys — measure those separately. Confirm product coverage and order extra for cuts.
Estimates only. See how this calculator works — the formulas, assumptions, and sources behind it.
From Roof Shape to Material List
Most calculators make you measure each plane and edge by hand. This estimator works the other way: choose the roof archetype that matches your home, and it derives the geometry for you — the sloped area for shingles and underlayment, plus the linear edge lengths that drive every accessory.
Gable
Two slopes meet at a ridge. Eaves run the length; gable ends are rakes. The most common home roof.
Hip
Four slopes run down to every wall. The ridge is shorter than the building, and four hips run from the corners — more cap and waste.
Shed
A single slope from a low wall to a high wall. Common on additions, modern homes, sheds, and garages.
Have an L-shaped roof, dormers, or an irregular footprint? Trace it with the draw roof tool, confirm your pitch, then bring the numbers to the material calculator for the full takeoff.
Roof Estimator FAQ
- How do I estimate roof area by roof type?
- Start with the footprint (length × width) the roof covers, then multiply by the pitch factor to get the true sloped area — the same for gable, hip, and shed roofs of equal pitch. This estimator does that automatically and also derives the edge lengths (eaves, rakes, ridge, hips) that each shape produces, so you can order accessories, not just shingles.
- Does a hip roof use more material than a gable?
- For the same footprint and pitch, the field shingle area is the same (footprint × pitch factor). The difference is in the accessories and waste: a hip roof has four sloped planes meeting at hips, so it needs hip cap and produces more angled offcuts — budget a higher waste factor (15%+) than a simple gable (10%). A gable has rakes and gable ends instead of hips.
- How do I find ridge, hip, and eave lengths?
- This tool computes them from your dimensions: eaves run along the bottom edges (a gable has two; a hip has the full perimeter), the ridge runs along the top (shorter on a hip than the building length), and hips run diagonally from each corner to the ridge on a hip roof. Enter your length, width, and pitch and the edge table updates live.
- What roof shapes does this support?
- Gable (two slopes to a ridge), hip (four slopes to all walls), and shed (a single slope). These cover most homes, sheds, garages, and additions. L-shaped roofs and dormers add valleys and are best measured section by section — use the draw roof tool for irregular footprints.
- How accurate is the estimate?
- The area and edge math is exact for a clean gable, hip, or shed at the pitch you enter. Material quantities use industry-typical coverage and round up. Real roofs have penetrations, overhangs, and complexity that change the numbers, so treat it as a strong planning list and confirm product coverage before ordering.