40x40 Metal Building: 2026 Prices and 7 Best Uses
A 40x40 metal building gives you 1,600 square feet of clear span floor in a square footprint. That shape works well for a four car garage, a compact shop or a small barndominium, and it fits on lots where a long building will not.
For 2026, a basic 40x40 kit costs about $22,400 to $27,200, and a finished turnkey building usually runs $48,000 to $72,000. Here is what goes into those numbers, seven popular ways to use the space and how to keep your price at the low end.
40x40 Metal Building Price
| Cost item | Per sq ft | 40x40 total |
|---|---|---|
| Kit only (12 ft eave) | $14 to $17 | $22,400 to $27,200 |
| Kit with 16 ft eave | $15.50 to $19 | $24,800 to $30,400 |
| Erection | $4 to $12 | $6,400 to $19,200 |
| 4 inch slab | $5 to $9 | $8,000 to $14,400 |
| Insulation (fiberglass) | $0.50 to $1.50 | $800 to $2,400 |
| Turnkey total | $30 to $45 | $48,000 to $72,000 |
The kit range uses the same $14 to $17 per square foot as our other 40 foot wide size guides, based on late 2022 prices moved forward with the BLS steel mill products index. Prices change with steel, location and options, so run your own spec through the metal building cost calculator.
Why square buildings cost a little more per foot
A 40x40 has the same end walls as a 40x80 but half the floor. End walls, corners and trim are fixed costs, so they make up a bigger share of the total on a short building. That is why a 40x40 often prices toward the top of the range per square foot. If you can stretch to 40x50 or 40x60, each extra bay usually adds space at a lower cost per foot.
7 Best Uses for a 40x40
1. Four car garage
Four 10 foot wide doors fit across one 40 foot side, with about 40 feet of depth for long trucks and a workbench at the back.
2. Workshop
A single 1,600 square foot room has space for a lift, a welding bay and storage racks. A 14 foot eave gives room for a two post lift.
3. Small barndominium
A 40x40 can hold a two bedroom home of about 1,600 square feet, or a 1,000 square foot home with a 600 square foot shop. See our barndominium guide for finish costs.
4. Farm equipment storage
Tractors, implements and hay fit under a clear span roof with no posts in the way.
5. Home gym or studio
Clear span floors make room for open gyms, dance studios and recording spaces.
6. Small retail or office
Many small commercial units are about this size, and a brick or stone front can make a steel building look like any storefront.
7. Church or community hall
A 40x40 seats roughly 100 people for worship or meetings. Our guide to metal church buildings covers larger options.
Foundation and Concrete
A 4 inch slab for a 40x40 needs about 19.8 cubic yards of concrete, or 21.7 yards with a 10% allowance for waste. Shops with heavy equipment or a car lift usually need 6 inches or thicker footings under the lift. Use our concrete slab calculator to price yours, and see the metal building foundation guide for anchor options.
| Slab thickness | Cubic yards | With 10% waste |
|---|---|---|
| 4 inches | 19.8 | 21.7 |
| 5 inches | 24.7 | 27.2 |
| 6 inches | 29.6 | 32.6 |
Eave Height and Doors
Most 40x40 buildings use a 12 to 16 foot eave. Twelve feet works for cars and a standard 10x10 door. Fourteen to 16 feet fits RVs, boats on trailers and lifts. Each door opening needs framing, which adds to the kit price, so plan the doors early. Our guide to metal building doors compares sizes and types.
How to Save on a 40x40
- Get at least three quotes for the same spec, including snow and wind loads.
- Keep a simple gable roof with a 1:12 pitch unless you need more.
- Order doors and windows with the kit so the openings are framed at the factory.
- Do the site prep and the slab with a local contractor and compare against turnkey bids.
- Check permits before you buy. Our permit guide explains what most counties want.
FAQ
How much does a 40x40 metal building cost?
About $22,400 to $27,200 for a basic kit and $48,000 to $72,000 for a turnkey building in 2026.
How much concrete do I need for a 40x40 slab?
About 19.8 cubic yards for a 4 inch slab, or 21.7 yards with 10% for waste.
How many cars fit in a 40x40 garage?
Four cars side by side, with room left over for storage or a workbench.
Sources
- U.S. Bureau of Labor Statistics, PPI series WPU1017, steel mill products, checked October 2026.
- Rex Metal Buildings size guides and cost calculator rates.
Ready to price your building? Get free metal building quotes from suppliers who serve your area, or use the form on this page and our team will be in touch.