Shed Calculator
Calculate lumber, sheathing, roofing, and siding materials for a DIY storage shed. Get accurate estimates with cost breakdowns.
How to Estimate Shed Materials
Building a storage shed starts with calculating how much lumber, sheathing, roofing, and siding you need. Measure the length and width of the shed footprint, choose your wall height and roof style, and this calculator handles the rest. It accounts for wall studs at 16-inch on-center spacing, top and bottom plates, roof pitch factors, and optional floor framing.
Popular Shed Sizes
| Size | Floor Area | Best For |
|---|---|---|
| 8 × 8 | 64 sq ft | Garden tools, mower storage |
| 8 × 10 | 80 sq ft | Lawn equipment, bicycles |
| 10 × 12 | 120 sq ft | Workshop, larger equipment |
| 12 × 16 | 192 sq ft | Workshop with workbench, ATV storage |
Gable vs. Lean-To Roof
A gable roof has two sloped sides meeting at a ridge, providing good water runoff and attic space for overhead storage. A lean-to (also called a single-slope or shed roof) slopes in one direction and is simpler to frame. Lean-to roofs work well when the shed is placed against a fence or wall, while gable roofs are better for freestanding structures.
Foundation Options
Every shed needs a level foundation. Common choices include a gravel pad (cheapest and easiest for small sheds), concrete blocks placed at each corner and midpoints, or a poured concrete slab for permanent, heavy-duty structures. For sheds under 120 sq ft, a gravel pad with pressure-treated skids is usually sufficient.
Building Tips
- Check local building codes and permit requirements before starting — many areas require permits for sheds over 100-120 sq ft.
- Use pressure-treated lumber for any framing that contacts the ground or foundation.
- Apply a weather-resistant barrier (house wrap) between sheathing and siding to prevent moisture damage.
- Install drip edge flashing along all roof edges before shingling to protect the fascia boards.
- Pre-stain or paint siding panels before installation — it is much easier to coat them while flat than after they are mounted.
Frequently Asked Questions
A 10x12 DIY shed typically costs between $1,500 and $4,000 for materials, depending on the quality of lumber, roofing, and siding you choose. Using basic framing lumber, OSB sheathing, and asphalt shingles puts you at the lower end. Upgrading to plywood sheathing, T1-11 siding, and architectural shingles pushes the cost higher. Labor — if you hire a contractor — can add another $1,000 to $3,000.
Permit requirements vary by municipality, but most areas require a building permit for sheds over 100 to 200 sq ft. Some jurisdictions also regulate setback distances from property lines and maximum height. Check with your local building department before starting construction. Even if a permit is not required, you may still need to comply with HOA guidelines.
The most affordable approach is a simple lean-to design with a gravel pad foundation, standard 2x4 framing, OSB sheathing, T1-11 siding (which doubles as sheathing and siding), and 3-tab asphalt shingles. Skipping the plywood floor and using a gravel pad directly saves additional cost. Sourcing materials during seasonal sales and using reclaimed lumber can also reduce expenses significantly.
Plywood is used for wall sheathing, roof sheathing, and flooring. For a 10x12 shed with 8-foot walls and a 6/12 gable roof, you would need roughly 10 sheets for walls, 5 sheets for the roof, and 4 sheets for the floor — about 19 sheets total. The exact number depends on wall height, roof pitch, and whether you include floor framing. This calculator provides a precise breakdown.
A gable roof provides symmetrical water drainage, more headroom, and space for overhead storage or a loft. It is the most popular choice for freestanding sheds. A lean-to roof is simpler and cheaper to build, uses fewer rafters, and works well for sheds attached to a house or fence. For most standalone storage sheds, a gable roof offers better functionality and curb appeal.