Roofing material calculator
A roofing material list comes from two kinds of numbers. The roof area sets the shingles, underlayment, nails and sheathing. The edge lengths set the drip edge, starter strip, ridge cap and ice and water shield. Type both and this calculator lists every quantity, using GAF's published coverage for each product. Our example roof, 2,200 sq ft with 17% waste, takes 78 bundles of shingles and 21 pieces of drip edge. Free, no account.
The roof
Type the roof area and the length of each line. It starts with the example house in the drawing: a 48 × 30 ft hip roof with a 24 × 22 ft gable wing, all at 6/12.
Measured on the slope
For shingles, underlayment and nails
Roof lines
Feet along each line. Rakes, hips and valleys climb, so measure them on the slope.
Ice and water shield
Deck and nails
100 for a full re-deck
Product coverage
Starting figures from the makers' spec sheets. Change them to match what you order.
GAF Timberline HDZ: 3
Timberline HDZ: 64
GAF Tiger Paw: 10 squares, before laps
GAF StormGuard: 36 in × 66.7 ft
GAF Pro-Start: about 120.33 ft
GAF Seal-A-Ridge: 4 bundles per 100 ft
Gibraltar: 10 ft lengths
- Eaves 176 ft
- Rakes 27 ft
- Ridges 52 ft
- Hips 90 ft
- Valleys 36 ft
| Material and how it was figured | Qty | Unit |
|---|---|---|
| Shingles2,200 sq ft + 17% waste = 25.74 squares × 3 bundles | 78 | bundles |
| Underlayment2,574 sq ft ÷ 1,000 sq ft a roll | 3 | rolls |
| Ice and water shield1 × 176 ft of eaves + 36 ft of valleys ÷ 66.7 ft a roll | 4 | rolls |
| Starter strip203 ft of eaves and rakes ÷ 120.33 ft a bundle | 2 | bundles |
| Hip and ridge cap142 ft of ridges and hips ÷ 25 ft a bundle | 6 | bundles |
| Drip edge203 ft of eaves and rakes ÷ 9 ft 10 in a piece, lapped 2 in | 21 | 10 ft pieces |
| Roofing nails1,648 shingles × 4 nails | 6,592 | nails |
| Sheathing10% of 2,200 sq ft ÷ 32 sq ft a sheet | 7 | 4 × 8 sheets |
Nails here are for the field shingles. Add nails for starter and ridge cap, and count flashing, vents and pipe boots on site.
Worked out in your browser from the numbers you type. Nothing is looked up or saved. No prices are shown here. Confirm every number on site.
How each material is figured
Each line uses a coverage figure from the maker's spec sheet. Change any of them under Product coverage to match what you order. Checked October 2026.
| Material | Figured from | Starting coverage | Source |
|---|---|---|---|
| Shingles | Roof area plus waste | 3 bundles a square (Timberline HDZ) | GAF Timberline HDZ specifications |
| Underlayment | Roof area plus waste | 1,000 sq ft a roll, before laps (Tiger Paw, FeltBuster) | GAF Tiger Paw sell sheet, GAF FeltBuster sell sheet |
| Ice and water shield | Eaves × courses, plus valleys | 66.7 ft a roll, 36 in wide (StormGuard) | GAF StormGuard data sheet, GAF WeatherWatch leak barrier |
| Starter strip | Eaves, plus rakes | About 120.33 ft a bundle (Pro-Start) | GAF Pro-Start starter strip |
| Hip and ridge cap | Ridges plus hips | 4 bundles per 100 ft (Seal-A-Ridge) | GAF Seal-A-Ridge sell sheet |
| Drip edge | Eaves plus rakes | 10 ft pieces, lapped 2 in | Gibraltar Building Products 2026 catalog, Drip edge code section (UpCodes) |
| Roofing nails | Shingles × nails each | 64 shingles and 256 nails a square (Timberline HDZ) | GAF Timberline HDZ specifications, GAF: shingle nails |
| Sheathing | Share of the roof area | 32 sq ft a 4 × 8 sheet | Sheet size |
Roll coverage for underlayment and ice and water shield is before laps, so the calculator adds your waste to the underlayment. Drip edge pieces lap 2 in, so each one covers 9 ft 10 in.
Take off a roof in five steps
The example house is a 48 × 30 ft hip roof with a 24 × 22 ft gable garage wing, all at 6/12. Its lines are worked out from the plan with the same pitch math as the rafter calculator.
- Get the sloped roof area: each plane's footprint times its pitch multiplier, added up.
- Measure the eaves, where water runs off the roof, and the rakes up the gable ends.
- Measure the ridges and hips for ridge cap, and the valleys for ice and water shield.
- Pick the waste for the roof shape and how many courses of ice and water shield go up from the eaves.
- Round every product up to whole bundles, rolls, pieces and sheets.
Example2,200 sq ft hip roof with a garage wing
- Shingles: 25.74 squares × 3
- 78 bundles
- Underlayment: 2,574 sq ft ÷ 1,000
- 3 rolls
- Ice and water: 176 ft of eaves + 36 ft of valleys
- 4 rolls
- Starter: 203 ft of eaves and rakes
- 2 bundles
- Ridge cap: 52 ft of ridge + 90 ft of hips
- 6 bundles
- Drip edge: 203 ft
- 21 pieces
- Nails: 1,648 shingles × 4
- 6,592
- Sheathing: 10% of the deck
- 7 sheets
Waste is 17%, Measured Bid's starting allowance for a complex roof.
How much ice and water shield you need
Multiply the eaves by the number of courses, add the valleys, and divide by the roll length. A 36 in roll covers one course about 3 ft up the roof.
GAF's WeatherWatch instructions run it up the roof to at least 24 in past the inside of the warm wall, and center one sheet in each valley. When the overhang plus the wall plus 24 in, measured on the slope, is more than one roll width, plan a second course. Local code decides where an ice barrier is required.
Ice and water rolls on the example house
| Coverage | Feet | Rolls |
|---|---|---|
| Valleys only | 36 | 1 |
| 1 course at the eaves, plus valleys | 212 | 4 |
| 2 courses at the eaves, plus valleys | 388 | 6 |
GAF StormGuard: 2 squares a roll, 36 in × 66.7 ft. WeatherWatch comes in 1.5 and 2 square rolls.
Roof sheathing: sheets to order
Divide the area you're replacing by 32 sq ft, the face of a 4 × 8 sheet, and round up. For spot repairs, type your best guess at the damaged share of the deck. For a full re-deck, use 100%.
The calculator adds no waste to sheathing, because a partial re-deck replaces whole sheets. Add a few for a full re-deck with many cuts.
4 × 8 sheets for the 2,200 sq ft example roof
| Deck replaced | Sq ft | Sheets |
|---|---|---|
| 10% | 220 | 7 |
| 25% | 550 | 18 |
| 50% | 1,100 | 35 |
| 100% | 2,200 | 69 |
Skip the tape for the area and the eaves
Enter an address and Measured Bid measures the roof from aerial roof data: the sloped area of every plane with its pitch, and the eaves where the gutters go. That covers the shingles, underlayment, nails and the eave side of the list before anyone climbs a ladder.
On our model house the roof measurement tool returns 2,344 sq ft, or 23.4 squares, and the gutter calculator finds 118 ft of eaves. Measure the rakes, ridges, hips and valleys from the plans or on site, and check every number before you order.
Planes
- North, 5/12962 sq ft
- South, 5/12962 sq ft
- East, 5/12210 sq ft
- West, 5/12210 sq ft
Price the roof with your rates
The material list is what you order. The price comes from your rates: in Measured Bid you set a price per square for each material, tear-off per layer, waste by roof type and a steep-roof adjustment, and any address becomes an estimate.
FAQ
How do I calculate roofing materials?
Start with the sloped roof area plus waste. That sets the shingles, underlayment and nails. Then measure the eaves, rakes, ridges, hips and valleys. They set the drip edge, starter strip, ridge cap and ice and water shield. Divide each by what one bundle, roll or piece covers and round up.
How many bundles of shingles do I need?
Divide the roof area by 100 for squares, add waste, and multiply by the bundles in a square. GAF Timberline HDZ is 3 bundles a square, so a 2,200 sq ft roof with 17% waste takes 78 bundles.
How much underlayment do I need?
Roof area plus waste, divided by what a roll covers. GAF's Tiger Paw and FeltBuster rolls cover 10 squares (1,000 sq ft) before laps, so a roof that needs 2,574 sq ft takes 3 rolls. Tiger Paw also comes in a 4 square roll.
How many rolls of ice and water shield do I need?
Multiply the eaves by the number of courses, add the valleys, and divide by the roll length. GAF StormGuard is 36 in by 66.7 ft, 2 squares a roll. One course on 176 ft of eaves plus 36 ft of valleys takes 4 rolls.
How much drip edge do I need?
Add the eaves and rakes and divide by what one piece covers once it's lapped. Gibraltar sells drip edge in 10 ft lengths, and codes based on the International Building Code lap pieces at least 2 in, so each piece covers 9 ft 10 in.
How many nails per square of shingles?
GAF lists 256 nails a square for Timberline HDZ: 64 shingles at 4 nails each. GAF says 4 nails a shingle is widely accepted as the industry standard, but warranty terms and building codes can call for more. Its Timberline UHD shingles need 6 nails each for wind warranty coverage up to 130 mph.
How many sheets of plywood does a roof need?
Divide the roof area by 32, the square feet in a 4 × 8 sheet, and round up. A full re-deck of a 2,200 sq ft roof takes 69 sheets before waste.
Can I get these measurements from an address?
The area and the eaves, yes. Measured Bid's free roof measurement tool returns the sloped area and pitch of every roof plane, and the gutter calculator returns the eaves. Take the rakes, ridges, hips and valleys from the plans or on site.
Related pages and tools
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