Shed Material Calculator
Get a materials list for building a shed from its size and roof pitch. The calculator counts the wall studs and plates, the plywood or OSB sheets for the walls and roof, the bundles of shingles, the siding, and the bags of concrete for a slab, and adds up an estimate from your prices.
- Choose US or Metric. You can still change the unit of any single field.
- Enter the Length of the shed along the ridge and the Width of the gable end, both measured outside the walls. The calculator works out a rectangular shed with a gable roof.
- Enter the Wall height, from the bottom of the bottom plate to the top of the top plate, and the Roof pitch, such as 6 for 6/12. Enter 0 for a flat roof.
- If the roof hangs past the walls, enter the Roof overhang, measured level from the outside of the wall. If the overhang at the eaves and at the gable ends is different, enter the larger one.
- Choose the Stud spacing and enter the number of Doors and windows. Under Framing details, check the top plate, the plate thickness, and the stock lengths.
- Choose the Sheet size, the Shingle bundle, and the siding profile you plan to buy.
- If the shed sits on a concrete slab, enter the Slab thickness and choose the bag size. Leave the slab thickness blank for a wood floor.
- Optionally, enter a price for each item to estimate the cost. Each price can be per piece, such as per sheet or per bundle, or by length, area, or volume.
Length fields accept whole numbers, decimals, fractions, and mixed
numbers, such as 12, 10.5, 3/4, or
92 5/8. Choose ft + in as the unit to enter a
length such as 8 ft 1 1/8 in in two fields.
How to calculate shed materials
The shed has four walls: the length, the width, the length, and the width. Each wall gets studs at both ends and studs in between, no farther apart than the stud spacing, the same way as the Framing Calculator:
Studs per wall = wall length ÷ stud spacing, rounded up, + 1
Extra studs = 4 corners × extra per corner + doors and windows × extra per opening
The studs, plus the waste allowance, are divided by the studs you can cut from each stock length. The plates run three times around the walls with a double top plate, or twice with a single top plate.
Walls and roof
Wall area = 2 × (length + width) × wall height + 2 gables
Each gable = width × (width ÷ 2 × pitch ÷ 12) ÷ 2
Roof area = (length + 2 × overhang) × (width + 2 × overhang) × √(1 + (pitch ÷ 12)²)
For a pitch in degrees, use the tangent of the angle in place of pitch ÷ 12. The wall area is used for both the wall sheathing and the siding, which both cover the walls and the gables from the bottom plate to the top plate. The roof area is used for both the roof sheathing and the shingles.
Sheets, bundles, siding, and bags
Sheets = area × (1 + waste % ÷ 100) ÷ sheet area, rounded up
Bundles = roof area × (1 + waste % ÷ 100) ÷ bundle coverage, rounded up
Siding pieces = wall area × (1 + waste % ÷ 100) ÷ (piece length × exposure), rounded up
Concrete bags = length × width × slab thickness × (1 + waste % ÷ 100) ÷ bag yield, rounded up
The wall and roof sheathing are counted separately, because roof sheathing is often thicker and bought as a different product. Vinyl siding sold in boxes is also shown as boxes.
Shed shape, products, and waste
Shed shape
Shed walls are framed like house walls. The City of Brandon's shed handout shows studs at 16 in (400 mm) or 24 in (600 mm) on center, a double top plate, and a single bottom plate, and Fine Homebuilding's Cottage Shed Plans frame the back wall with 2x4s at 16 in on center. The calculator uses the same stud layout, corners, and openings as the Framing Calculator, with 4 corners and no interior walls.
Doors and windows add studs at the openings, but their area isn't taken off the walls. CertainTeed's siding estimating guide measures walls including doors and windows, and the Fine Homebuilding plans sheathe the walls with full sheets and cut the openings out afterward. For a small shed with a wide door, the sheathing and siding come out a little high.
Sheets, bundles, siding, and bags
The sheet sizes, shingle bundles, siding profiles, and concrete bags are the same as in the Plywood Calculator, the Roofing Calculator, the Siding Calculator, and the Concrete Calculator, which explain where each size comes from. Check the coverage and sizes on the products you buy.
The 10% waste allowance applies to every material. It's the recommended allowance in each of those calculators. To use a different allowance for one material, such as 15% for shingles on a roof with valleys, work out that material in its own calculator.
Concrete slab
The slab is the length × width of the shed, at the same thickness all over. Sheds are also built on wood floors on skids or pavers, so leave the slab thickness blank if you won't pour a slab. The City of Brandon's handout allows a 100 mm (about 4 in) slab for sheds under 55 m² (592 ft²) and asks for a thicker slab with thickened edges for larger ones, so check the requirements where you build.
Examples
A 12 × 10 ft shed
A 12 × 10 ft shed with 8 ft walls, a 6/12 roof, a door, a window, and a 4 in slab needs 55 studs (92 5/8 in) and 19 plates of 8 ft. The walls are 352 ft² plus two gables of 12.5 ft², or 414.7 ft² with 10% waste: 13 sheets of 4 × 8 ft and 50 pieces (3 boxes) of double 4 in vinyl siding. The roof is 134.16 ft², or 147.58 ft² with waste: 5 sheets and 5 bundles of shingles. The slab is 1.63 yd³ with waste, or 74 bags of 80 lb concrete.
At $4.25 per stud, $5.10 per plate, $32.50 and $38.00 per wall and roof sheet, $35.50 per bundle, $90 per box of siding, and $6.50 per bag, the materials cost $1,871.65. With a 6 in overhang, the roof grows to 175.87 ft² with waste, or 6 sheets and 6 bundles.
A Metric shed
A 4 × 3 m shed with 2.4 m walls, a 30° roof, one door, and a 10 cm slab needs 53 studs and 20 plates of 2.4 m, 14 + 6 sheets of 1220 × 2440 mm for the walls and roof, 6 bundles of 3 m² shingles, 54 boards of 150 mm uPVC shiplap, and 143 bags of 20 kg concrete.
FAQ
With 8 ft walls, a 6/12 roof, a door, a window, and 10% waste: about 55 studs, 19 plates of 8 ft, 13 sheets for the walls and 5 for the roof, 5 bundles of shingles, and 50 pieces of double 4 in vinyl siding. A 4 in slab takes 74 bags of 80 lb concrete.
Divide the wall area, including the gables, by 32 ft² for 4 × 8 ft sheets, and do the same for the roof area. A 12 × 10 ft shed with 8 ft walls and a 6/12 roof needs 13 sheets for the walls and 5 for the roof, with 10% waste.
Multiply the length, width, and thickness for the volume, add 10%, and divide by the yield of a bag. A 12 × 10 ft slab 4 in thick is 40 ft³, or 44 ft³ with waste, which is 74 bags of 80 lb concrete at 0.60 ft³ each.
It depends on your local prices, so enter the price of each item to get the cost of the materials. With the example prices above, the materials for a 12 × 10 ft shed come to $1,871.65. The estimate doesn't include labor, doors, windows, hardware, or a shed kit.
Related calculators
- Framing Calculator
How many studs and plates to buy for wood-framed walls, with corners, openings, and the cost.
- Plywood Calculator
How many sheets of plywood or OSB to buy for subfloors, walls, and roofs, by sheet size.
- Roofing Calculator
Roof area from its size and pitch, in squares, and how many bundles of shingles to buy.
- Siding Calculator
How many pieces and boxes of vinyl or fiber cement siding to buy for the walls and gables.
- Concrete Calculator
Concrete volume and how many bags of concrete mix to buy.
- Roof Truss Calculator
How many trusses a gable roof needs, with the rise, truss height, and top and bottom chord lengths.