Turn your roof area or roofing squares into a complete asphalt shingle bill of materials — field shingles, starter, ridge cap, underlayment, drip edge, ice-and-water and nails — with waste built in, so you don’t under-order at the supplier. Already measuring panels? Use the metal roofing calculator instead.
How will you enter the roof size?
The actual sloped surface area, not the flat footprint. Measure it on the roof area calculator.
One roofing square = 100 ft² of roof. For the area↔squares conversion and "what is a square", see the roof area calculator.
Flat area seen from above (ft²).
Used for the slope multiplier.
Quick estimate only. The roof area calculator is the canonical measurement page for multi-plane, hip and L-shaped roofs; the roof pitch calculator explains the multiplier.
Shingle type (sets bundles per square)
10–15% is normal; lean toward 15% for lots of hips, valleys and cuts.
Linear edge lengths
Drive starter, ridge cap, drip edge and ice-and-water. Leave at 0 if unknown — those line items will read 0. The roof area calculator helps you measure them.
When on, estimates rolls from a 3 ft eave strip plus valley area. Confirm extent with local code.
Your own local price for field shingles per square — no prices are baked in. Leave blank to skip cost.
An estimating aid using standard roofing-square and coverage conventions, all adjustable. Bundle, roll and piece coverage vary by product, region and supplier — confirm exact figures before ordering, and order against measured roof planes rather than a footprint.
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Measuring and framing the roof?
Get the area first on the Roof Area Calculator (square footage and squares), and the slope on the Roof Pitch Calculator (pitch, angle and multiplier). Going metal instead of asphalt? The Metal Roofing Calculator handles panels, screws and trim.
The whole bill of materials, not just shingles
The most common complaint about a roofing calculator or shingle calculator is that it gives you a bundle count and stops there — so you drive to the supplier, buy shingles, and discover you still need starter, ridge cap, underlayment, drip edge, nails and, in a cold climate, ice-and-water shield. Field shingles are the easy part; the accessories are where orders fall short. As a full roofing estimator this tool builds the complete list from one set of inputs — going straight from squares to bundles and on to every accessory — so the second supplier run doesn’t happen.
It takes your roof area or roofing squares as the starting point. If you only have a plan footprint, the footprint-plus-pitch mode applies the slope multiplier for a quick estimate — but the dedicated roof area calculator is the place to measure a real roof with multiple planes, hips or an L-shaped layout, and this tool links straight to it.
Shingles and bundles per square
A roofing square is 100 ft² of finished roof. The number of bundles in a square is not always three — that’s the assumption that makes a thin shingle estimator under-count heavier products:
3-tab / standard — about 3 bundles per square.
Heavy architectural / dimensional — about 4 bundles per square (heavier bundles, less coverage each).
Premium / designer — about 5 bundles per square, sometimes 6.
squares = roof area ÷ 100 adjusted squares = squares × (1 + waste%) field bundles = adjusted squares × bundles-per-square (round up to whole bundles)
Always add a waste allowance before converting to bundles — roughly 10% for a simple gable, 12% typical, and 15% for cut-up roofs with lots of hips, valleys and dormers where there is more cutting.
Underlayment, nails and the area-based items
Underlayment covers the whole deck, so it scales with area. Coverage per roll varies by product, but typical published figures are about 400 ft² for #15 felt (4 squares), 200 ft² for #30 felt (2 squares) and 1,000 ft² for synthetic (10 squares). Add roughly 10% for the overlap at each course.
underlayment rolls = roof area × 1.10 ÷ roll coverage nails = squares × 320 (4-nail) or × 480 (6-nail high-wind) nail boxes = nails ÷ 7,200 · ≈ 2.5–3 lb / square
Starter strip, ridge cap and drip edge — the linear items
Starter, ridge cap and drip edge are sold by length, so they come from your edge lengths, not your area. A starter bundle covers roughly 100–120 linear feet of eave and rake; a ridge/hip cap bundle covers roughly 20–25 linear feet; drip edge comes in 10 ft sticks for eaves and rakes with about 10% added for overlap.
In cold climates, code commonly calls for ice-and-water shield along the eaves and in the valleys to guard against ice-dam backup. With the cold-climate option on, this calculator estimates rolls from a 3 ft eave strip plus valley coverage against a typical 200 ft² roll — a starting point to confirm against your local code.
ice-&-water rolls = ceil((eave_lf × 3 ft + valley area) ÷ 200 ft²)
What a calculator can’t give you: penetration flashings
Pipe boots, step and wall flashing, chimney and skylight flashing cannot be derived from roof area or edge lengths — they depend on what actually penetrates your roof. The results flag these to verify on site; count the penetrations yourself and add them to the order. Leaks overwhelmingly start at these transitions, so they are worth getting right.
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Frequently asked questions
How much roofing material do I need?
Start from the actual sloped area (not the footprint), divide by 100 for squares, and add 10–15% waste before converting to materials. Field shingles run ~3 bundles/square for 3-tab, 4 for heavy architectural, 5 for premium. A full order also needs starter, ridge cap, underlayment, drip edge, nails and — in cold climates — ice-and-water. This tool builds that whole list so you don’t under-order the accessories.
How many bundles of shingles are in a square?
It depends on the shingle. Standard 3-tab is about 3 bundles per square; heavy architectural is often 4 because each bundle covers less; premium/designer can be 5 or 6. Pick the type above so the bundle count matches what you’re actually buying instead of assuming everything is 3.
How many shingles do I need for my roof?
Area ÷ 100 = squares; × (1 + waste%) × bundles-per-square = field bundles. A 2,000 ft² roof is 20 squares; architectural at 3/square with 12% waste is 20 × 1.12 × 3 ≈ 67, rounded up to 68 bundles. Starter and ridge cap are counted separately from edge lengths.
Does this include underlayment, drip edge and nails?
Yes — that’s the point. Most calculators stop at bundles, which is why people under-order. From your area it sizes underlayment rolls and nails (count, pounds and boxes); from your edge lengths it sizes starter, ridge cap, drip edge and ice-and-water. Penetration flashings can’t come from area, so they’re flagged to verify on site.
How much does a bundle of shingles weigh and cover?
Roughly: a 3-tab bundle covers about a third of a square (~33 ft²) and weighs ~50–80 lb, so 3 make a square. Heavy architectural bundles cover less area each — about a quarter of a square — hence 4 per square. Exact coverage and weight are set by the specific product, so this tool works from the bundles-per-square figure you choose.
How do I work out ridge cap, starter strip and drip edge?
They’re linear, so they come from edge lengths: starter from eaves + rakes (~110 lf/bundle), ridge cap from ridge + hips (~25 lf/bundle), drip edge in 10 ft sticks for eaves + rakes (+10% overlap). Enter those lengths and the calculator converts each.
Do I need ice-and-water shield, and how much?
It’s a self-adhering waterproof underlayment for eaves and valleys against ice-dam backup; whether it’s required depends on climate and local code. Turn on the cold-climate option and the tool estimates rolls from a 3 ft eave strip plus valleys against a ~200 ft² roll — then confirm the required extent locally.
How is this different from the roof area and roof pitch calculators?
The roof area calculator is geometry (footprint + pitch → sloped area, square footage, squares). The roof pitch calculator handles slope and the multiplier. This tool takes area or squares and turns them into the asphalt bill of materials. For panels, screws and trim, use the metal roofing calculator.