Quick answer
A roofing square is a unit of area equal to 100 square feet of roof surface, a 10-by-10-foot patch, and it is the unit in which shingles are sold and most roofing quotes are priced.
Squares are counted on the sloped roof, not the house footprint, so a steeper roof has more squares than its floor plan suggests. A quote's square count drives its material, labor and disposal lines.
Quick facts
- Equals
- 100 sq ft of roof surface (10 ft × 10 ft) 3
- Bundles per square
- Usually 3 for standard shingles (one data sheet: 20 shingles and 33.3 sq ft per bundle); heavier lines can need 4 or more 13
- Counted on
- The sloped roof surface, not the footprint
- Convert
- Roof sq ft ÷ 100 = squares
- Priced separately
- Starter, ridge cap, flashing, vents and deck repair
- Abbreviated
- SQ or sq. on quotes and measurement reports
Key takeaways
- A roofing square is 100 square feet of roof surface, a 10-by-10-foot patch.
- Squares are measured on the sloped roof, so a steep roof has more squares than its floor plan.
- Most standard shingles come 3 bundles to a square, about 33.3 square feet per bundle.
- Edges and joins, like drip edge, starter and ridge cap, are counted in linear feet, not squares.
- When you compare quotes, ask for measured squares and the waste allowance as two separate numbers.
Why roofers count in squares
Shingles are packaged so that a set number of bundles covers 100 square feet. Pricing labor, tear-off and materials per square lets a contractor scale one number to any house. On a quote you will see it as "SQ" or "squares", often with a single per-square price that bundles materials and labor together.
The square is a surface measure. A roof is sloped, so its surface is larger than the ground it covers. The ratio depends on roof pitch: a 6/12 roof has about 12 percent more surface than its footprint, and a 12/12 roof about 41 percent more.
Squares = (footprint × pitch multiplier) ÷ 100
footprint- Length × width of each roof plane seen from above, in sq ft, with overhangs
pitch multiplier- 1.054 at 4/12, 1.118 at 6/12, 1.202 at 8/12
100- Square feet in one roofing square
Waste for cuts is added after this, and each bidder sets it.
The formula shows why two bids can differ: pitch and waste change the count, not the size of your house.
How to count squares
- Measure the footprint the roof covers, including overhangs (length × width for each rectangle).
- Multiply by the pitch multiplier for that plane (1.054 at 4/12, 1.118 at 6/12, 1.202 at 8/12).
- Add every plane together. That is the roof surface in square feet.
- Divide by 100. That is the measured number of squares.
- Add a waste allowance for cuts at valleys, hips and edges. The bidder decides it; ask what they used.
The squares calculator does steps 1–4 for you from footprint and pitch.
Worked example: one house, measured and ordered
A gable roof over a 40 × 30-foot footprint with 1-foot overhangs all round, pitch 6/12:
| Step | Calculation | Result |
|---|---|---|
| Flat area with overhangs | 42 ft × 32 ft | 1,344 sq ft |
| Roof surface | 1,344 × 1.118 (6/12) | 1,503 sq ft |
| Measured squares | 1,503 ÷ 100 | 15.0 squares |
| Shingle bundles (3 per square) | 15.0 × 3 | 45 bundles |
| With a 10% waste allowance (example) | 15.0 × 1.10 | 16.5 squares ordered |
Illustrative house. The 3-bundles-per-square figure is typical but product-specific 3; a waste allowance is a bidder's choice, not a fixed rule. Starter strip and ridge cap are counted in linear feet on top of this.
Types of squares: what is in one bundle and one square
One manufacturer's published data sheet shows how the numbers fit together. Other products differ, so always read the sheet for the shingle on your quote.
| Item | Published figure |
|---|---|
| Shingles per bundle | 20 |
| Coverage per bundle | 33.3 sq ft |
| Coverage of three bundles | 100 sq ft (one square) |
| Exposure (the part you see on each row) | 5⅞ in |
| Bundles per pallet | 56 |
So for this product, one square is 3 bundles, or 60 shingles. A 25-square roof needs 75 bundles before waste, starter and ridge. The data sheet is also where you check the shingle's impact and wind ratings.
Squares for metal, tile and flat roofs
The square is not only for shingles. Metal, tile, slate and low-slope membrane roofs are also usually quoted per square, because it is the easiest way to compare one roof with another. The materials are just bought in other units.
Metal panels are ordered by panel length and count, cut to fit each roof plane.
Tile and slate are ordered by the number of pieces, and the maker lists how many pieces cover a square for each profile and exposure. Membranes for flat roofs come in rolls of a set width and length.
In every case, the roofer converts the measured squares into the units the supplier sells.
The parts of a roof that are counted in feet, not squares
Squares measure the big flat areas. The edges and joins of a roof are measured in linear feet instead, because they are long and thin.
A measurement report lists them separately: the length of eaves (bottom edges), rakes (sloped side edges), ridges (the top line), hips (outside corners where two planes meet) and valleys (inside corners).
Each one drives a different item on your quote. Eaves and rakes get drip edge, which the code requires on shingle roofs 2.
Eaves also get the starter strip and, in cold areas, the ice barrier. Ridges and hips get ridge cap shingles. Valleys get valley lining or flashing.
None of these are inside the per-square shingle price unless the quote says so.
Why some roofs waste more material than others
Shingles are rectangles. Every time a row hits a hip, a valley, a dormer or a skylight, the roofer has to cut a shingle to fit, and the offcut is often too small to use anywhere else.
A plain two-sided gable roof has few of these cuts. A roof with many hips, valleys and dormers has hundreds.
That is why the waste allowance is a choice the estimator makes for your roof, not a number you can look up. Two honest bids can use different allowances.
What you can check is that each bid states it, and that a roof full of valleys did not get the same allowance as a plain box.
Why the square is a useful unit
For you
- One number lets you compare the size of the job across quotes
- You can check it yourself from the footprint and pitch
- Per-square prices let you see whether two bids are close
For the roofer
- Materials are packaged to match it, so ordering is simple
- Labor, tear-off and disposal scale with it
- Measurement reports use it, so everyone works from the same base
Where squares can mislead you
- A square count says nothing about quality: two quotes with the same squares can use very different shingles and underlayment.
- It hides the linear-foot items. A low per-square price can leave out drip edge, ridge cap or ice barrier.
- It does not show complexity. A cut-up roof with many valleys costs more per square to install than a plain gable.
- It does not include deck repairs, which are found only after tear-off.
Where squares appear on a quote
Most quote lines are either per square or per linear foot. Knowing which is which lets you compare bids line by line.
| Line item | Usually priced by | What to check |
|---|---|---|
| Shingles / roof covering | Square | Measured squares and waste shown separately |
| Tear-off and disposal | Square (per layer) | How many existing layers they priced |
| Underlayment | Square | Single or double layer (shingles between 2/12 and 4/12 need two layers 2) |
| Ice barrier | Square or linear foot of eave | How far up from the eave it runs |
| Drip edge, starter, ridge cap | Linear foot | Included or extra |
| Deck (sheathing) replacement | Per sheet | The per-sheet price, since the count is unknown until tear-off |
Tear-off squares and the deck underneath
On a reroof, the old roof has to come off first. Tear-off is usually priced per square, and per layer: a roof with two old layers of shingles is roughly twice the removal work and twice the waste to haul away as a roof with one.
Ask each roofer how many old layers they counted and how they checked, because a bid that assumes one layer on a two-layer roof will grow once work starts.
Only after tear-off can anyone see the condition of the wooden deck.
That is why damaged deck boards or sheets are priced separately, usually per sheet, and why the final number of sheets is not known on the day you sign.
A good quote states the price per sheet up front, so the extra cost is predictable if rot is found.
Keep your roof numbers for later
Once the new roof is on, keep the paperwork. The measurement report, the number of squares installed, and the exact shingle name and color all help later. A roofer fixing storm damage can order the right amount and the same product. An insurance adjuster can check the size of the roof against your records.
Many homeowners also keep a spare bundle of the same shingles in the garage or attic. Shingle color can vary between production runs, so a few spares from your own roof make small repairs match far better than a new bundle bought years later.
Warning signs on a quote
- The square count is lower than the measurement report without a clear reason.
- There is no waste allowance stated, or the same allowance is used for a plain roof and a complex one.
- Tear-off is priced for one layer when your roof has two.
- Drip edge, starter, ridge cap or ice barrier are missing entirely.
- There is no per-sheet price for deck repair, so any rot found later is open-ended.
- The fastening is not stated. The code requires at least four fasteners per strip shingle, or more if the maker says so 4.
Code rules that change how many squares of material you need
The square count of the roof does not change with the rules, but the materials per square do. On shingle roofs between 2/12 and 4/12, the code requires two layers of underlayment instead of one 2.
The shingle makers' trade association describes the same 2/12 to 4/12 range as "lower slope", where water drains more slowly and is more likely to back up 5. That roughly doubles the underlayment per square on those planes.
In cold areas where ice damming is a recorded hazard, the code also requires an ice barrier from the eave to at least 24 inches inside the wall line 2. That membrane is extra material on the lowest part of every plane, usually priced per square or per foot of eave.
Comparing bids with different square counts
Three contractors can measure the same roof and write three different numbers.
Usually the measured area agrees and the waste allowance differs: a complex roof with many valleys and dormers wastes more material than a plain gable.
Ask each bidder for two numbers, measured squares and the waste they added, before comparing the price per square.
A low square count is not good news on its own. If it is below the measured area, the crew will run out of material or the bill will grow mid-job. A measurement report from aerial imagery, which many contractors order, gives a neutral area to compare against.
Price per square vs price per square foot
They are the same price at different scales: divide a per-square price by 100 for the per-square-foot figure. The catch is what each one is "per".
A roofing per-square price is per 100 square feet of roof surface; a per-square-foot figure in a cost article may be per square foot of house or footprint, which is smaller on any pitched roof. Check the basis before you compare. Sourced, dated prices are on our cost page.
Common mix-ups
- Myth A 2,000-square-foot house needs 20 squares.
- Reality Only if the roof were flat and had no overhangs. House size is floor area; squares are roof surface. A two-storey 2,000 sq ft house has about half that footprint, and pitch then adds surface.
- Myth Three bundles always make a square.
- Reality Most standard shingles are packaged that way, but some heavier designer lines need four or more bundles per square. The product spec says.
Sources: [3]
Does a square change by location?
No. A square is 100 square feet everywhere. What changes from place to place is the price per square, which depends on local labor costs, material prices, permits and disposal fees.
That is why this page does not quote a price. Our price pages show sourced, dated figures and explains what drives them in different markets.
Local code can also change the material per square, for example where an ice barrier or extra fastening is required.
How to check the squares on your quote
- Find the measured squares on each quote, or ask for them. Ask for the measurement report if the roofer ordered one.
- Check the pitch they used against your own measurement from the attic.
- Ask what waste allowance they added, and why.
- Check that tear-off is priced for the number of old layers on your roof.
- Check the linear-foot items (drip edge, starter, ridge cap, ice barrier) are listed, not missing.
If two quotes differ by several squares, it is usually waste or a missed plane, like a porch roof. Ask both roofers to explain the gap before comparing prices.
Keep going
- Roofing calculatorFootprint and pitch to squares
- Roof cost calculatorSquares to a sourced price range
- Roofing cost guideSourced, dated prices
- Choosing a rooferWhat a complete quote includes
- Roof plannerSee roof options for your house in a few steps
Questions about roofing square
How many square feet is a roofing square?
100 square feet of roof surface, the area of a 10-by-10-foot section. It is measured on the slope of the roof, not on the floor plan.
How many bundles of shingles are in a square?
Usually three for standard three-tab and architectural shingles, so each bundle covers about 33 square feet. Some heavier designer lines need four or more bundles per square; the manufacturer lists it on the product spec and the bundle wrapper.
How many squares is a 2,000 square foot house?
It depends on the footprint, the overhangs and the pitch, not the floor area. A single-storey 2,000 sq ft house at 6/12 with overhangs might be around 23–25 squares; the same floor area on two storeys roughly halves the footprint and the squares. Measure the roof, not the house.
Does a square include waste?
No. A square is a unit of area. The waste allowance is added on top by the contractor, and it varies with how cut-up the roof is. Ask for measured squares and ordered squares separately.
Is price per square the same as price per square foot?
Yes, scaled by 100, as long as both are per square foot of roof surface. Many cost articles quote per square foot of house instead, which reads lower on a pitched roof.
How much does one bundle of shingles cover?
For most standard shingles, about 33.3 square feet, a third of a square. One published data sheet lists 20 shingles and 33.3 square feet per bundle. Heavier designer shingles can cover less per bundle, so check the product.
Are ridge caps counted in squares?
No. Ridge and hip caps are counted in linear feet along the ridges and hips, and they are often a separate product from the field shingles. Starter strip and drip edge are linear-foot items too.
Why did my roofer order more squares than the measurement report?
Because the report gives measured area and the roofer adds waste for cuts at hips, valleys, dormers and edges. A cut-up roof needs more extra material than a plain one. Ask for the allowance in writing.
Sources
- IKO, Dynasty technical data sheet (04/2026), retrieved .
- International Code Council, 2021 International Residential Code §R905.1.1 Underlayment (Maryland adoption, read at UpCodes), retrieved .
- IKO, "Bundles of IKO Shingles in a Square" (2020), retrieved .
- International Code Council, 2021 International Residential Code §R905.2 Asphalt shingles (read at UpCodes), retrieved .
- Asphalt Roofing Manufacturers Association, "Installation of Asphalt Shingles on Lower Sloped Roofs" (July 14, 2025), retrieved .
Expert review
Written by the HyreRoof editorial team. Not yet reviewed by an outside expert. We say so rather than imply a review that has not happened; see our editorial policy.
How the numbers were checked: Unit definition and bundle packaging checked against a manufacturer's published guidance; worked example calculated from stated inputs.
Suggest a correction. We fix errors and say what changed.