Building a shed from scratch starts with an accurate lumber list. Buy too little and you lose a day to extra hardware store runs. Buy too much and you’re paying for boards you’ll never use. This calculator works out the framing for your shed’s floor, walls, and roof piece by piece: skids, joists, studs, plates, headers, rafters, sheathing, and roofing. It then prices the list at current lumber prices.
Enter your shed’s size, roof, and openings below. Open “Edit material prices” to plug in your local lumber prices, then print the list to take to the store.
Example: Materials for a 10×12 Shed
Here’s what the calculator lists for a typical 10×12 gable shed with 8-foot walls, a 4/12 roof pitch, 12-inch overhangs, a wood floor on skids, T1-11 siding, a 4-foot door, one window, and 10% waste:
| Material | Quantity |
|---|---|
| 4×6 PT skids (12 ft) | 3 |
| 2×6 PT floor joists (10 ft) + rim joists (12 ft) | 10 + 2 |
| 3/4″ tongue-and-groove subfloor | 5 sheets |
| 2×4 wall studs (8 ft) | 57 |
| 2×4 plates (12 ft) | 12 |
| 2×4 rafters (8 ft), 24″ on center | 20 |
| T1-11 siding panels | 12 sheets |
| 7/16″ OSB roof sheathing | 7 sheets |
| Asphalt shingles | 6 bundles |
| Estimated materials cost | about $2,200 |
The full list also includes gable studs, headers, a ridge board, rafter ties, underlayment, drip edge, and a fasteners-and-hardware allowance. The total doesn’t include the door, window, trim, or paint. Use our shed paint calculator for paint, and our shed cost calculator for a full project budget including labor.
Floor Framing
Most wood sheds sit on pressure-treated 4×6 skids (runners) laid on a gravel pad or concrete blocks. Two skids are enough for narrow sheds, and wider sheds need three or four. Skids also make it possible to move the shed later.
Floor joists run across the width of the shed at 16 inches on center, with a rim joist along each long side. Because they sit close to the ground, joists and rims should be pressure-treated lumber rated for ground contact. 2×6 joists are standard when skids are close together. Longer spans between supports call for 2x8s. The floor is finished with 3/4-inch tongue-and-groove plywood or OSB, which stays flat and won’t bounce between joists.
Building on a concrete slab instead? You can skip the floor framing entirely and use pressure-treated bottom plates anchored to the concrete. Our slab thickness calculator will help you size the slab.
Wall Framing
Shed walls are almost always framed with 2×4 studs. Spacing them 16 inches on center gives the strongest wall and the best nailing for siding. 24 inches on center uses fewer studs and works for many small sheds, but check what your siding requires. Each wall gets one bottom plate and a doubled top plate that overlaps at the corners to tie the walls together.
Beyond the regular studs, plan for extras:
- Corners: about two extra studs per corner so the siding has something to nail to inside and out
- Openings: a full-height king stud and a shorter jack stud on each side of every door and window
- Headers: doubled 2x6s over doors up to about 4 feet wide, and 2x8s over wider doors
- Gable ends: short studs filling the triangle between the top plate and the end rafters
Roof Framing
On a gable roof, rafters run from each wall up to a ridge board, with horizontal rafter ties that keep the walls from spreading. The ridge board is usually one size larger than the rafters. A lean-to roof slopes one way, from a taller front wall to a shorter back wall. It needs no ridge board, but each rafter spans the full width of the shed.
Rafter size depends on the span. Short spans on small sheds can use 2x4s. Wider sheds and areas with heavy snow need 2x6s or 2x8s, and very wide sheds often use pre-built trusses instead. Overhangs protect your siding from rain but lengthen each rafter, so the calculator adds them to the rafter length and roof area. If you plan to use asphalt shingles, keep the pitch at 4/12 or steeper when you can. Shingles can go on slopes down to 2/12, but only with a double layer of underlayment.
Sheathing, Siding, and Roofing
Standard 4×8 panels cover 32 square feet each. Most sheds use one of two wall options:
- T1-11 siding panels: these act as both sheathing and finished siding in one layer. They’re the fastest and most common choice for sheds.
- OSB sheathing plus separate siding: use this if you want lap siding, vinyl, or board-and-batten. It adds material and labor but can match your house.
The roof deck is typically 7/16-inch or 1/2-inch OSB, covered with underlayment, drip edge along the edges, and shingles. Shingles are sold in bundles, and it takes three bundles to cover one “square” (100 square feet), plus a little extra for the starter course and ridge caps.
Lumber Prices in 2026
At big-box stores, standard SPF #2 framing lumber currently starts around $3.85 for an 8-foot 2×4, $5.85 for a 2×6, and $8.45 for a 2×8. Longer boards cost proportionally more. Pressure-treated lumber costs more than untreated, and sheet goods like OSB swing widely by region and season. That’s why every price in the calculator can be edited. Plug in your local store’s prices for the most accurate total.
A few ways to save:
- Compare a local lumber yard against the big-box stores. Yards often match prices on full orders and have better-quality boards.
- Buy the whole list at once for bulk pricing and free or discounted delivery, but keep the lumber covered and off the ground until you use it.
- Choose board lengths that divide cleanly into your cuts. For example, a 12-foot board cuts into three 4-foot pieces with no waste.
How Much Extra Should You Buy?
Framing lumber usually loses 5–10% to cuts, mistakes, and boards too warped to use. Sheet goods often lose 10–15%, because openings and odd angles leave offcuts. The calculator applies the waste setting you pick (10% by default) to studs, plates, rafters, and sheet goods. Joists, skids, and rims are counted exactly. It’s also smart to hand-pick your studs at the store and skip any that are badly bowed or twisted.
Building Codes and Permits
The member sizes the calculator suggests are typical for small sheds in areas with light to moderate snow loads. Your local code may require larger rafters, closer spacing, hurricane ties, or a specific foundation, especially in heavy-snow or high-wind areas. Many towns also require a permit above a certain size. Check our shed permit guide and confirm the details with your building department before you order.
Shed Framing FAQs
How many 2x4s do I need to build a 10×12 shed?
With studs 16 inches on center, a 10×12 shed with one door and one window needs about 55–60 wall studs including waste. Add a dozen or so 12-foot 2x4s for plates, a couple for the gable ends, and 2×4 rafters and ties if the roof span is short enough. The calculator gives you the exact count for your design.
Should I use 16-inch or 24-inch spacing?
16 inches on center is the safer default for walls, because it’s stiffer and works with nearly every siding. 24-inch spacing is common for shed rafters and can work for walls on small sheds, but check your siding and roofing manufacturer’s requirements first.
Rafters or trusses?
Site-built rafters are simple and inexpensive for most backyard sheds. Pre-built trusses make more sense for wide sheds, heavy snow loads, or when you want to set the roof quickly. They’re ordered to your exact size, so get quotes early.
Is it cheaper to build a shed or buy a kit?
Building from scratch is often cheaper on materials, and you get a stronger, custom-sized shed. Kits save planning and cutting time. Compare both with our shed cost calculator, or start with a proven design from our list of the best shed plans.