Size the lumber and soil for one bed or a whole garden — no guesswork.
Estimates are planning aids, not a professional quote. Double-check quantities and product coverage — and any local code or permit requirements — before you buy.
| Lumber & Decking | $171–$217 |
| Soil & Fill | $77–$99 |
| Fasteners & Hardware | $10–$12 |
| Total | $258–$328 |
Excludes tools, delivery, tax and permit fees. Labor not included — this is a DIY materials estimate.
These are affiliate links: we may earn a commission if you buy through them, at no extra cost to you. It never changes what the calculator recommends — the shopping list comes from your dimensions, not from what pays.
About this calculator
Give the Raised Garden Bed Builder a size, wall height and material and it returns the exact board count, corner hardware, and — the part everyone gets wrong — how much soil to buy, in both cubic yards and bags.
Building several beds? Set the quantity and everything scales at once. Advanced options add a fabric liner, a hardware-cloth gopher barrier, board width and corner style.
Step by step
A step-by-step walkthrough to go with your plan above. Follow the product instructions and any local code or permit requirements as you work.
Choose a level area with at least 6–8 hours of sun and easy access to water. Mark the bed's footprint and clear it; you can leave the grass and smother it later with cardboard.
Cut the side boards to your length and width, and the corner posts to the finished wall height. Dry-fit one course on the ground to confirm everything fits square before fastening.
Screw the side boards to the inner corner posts (or to metal brackets), keeping the box square by checking the diagonals. Stack and fasten additional courses for taller beds.
Set the assembled frame on the marked spot, then dig down or shim until it sits level all the way around. A level bed waters and drains evenly.
Staple a fabric liner to the inside walls to slow rot and block weeds, and lay hardware cloth across the bottom if burrowing animals are a problem in your area.
Lay overlapping cardboard across the bottom to smother the grass below — it breaks down as the roots grow past it, so you don't have to remove the sod.
Fill with a raised-bed mix (or topsoil plus compost), watering and tamping lightly in layers. Slightly overfill, since the soil settles an inch or two after the first good watering.
Plant, mulch the surface to hold moisture, and check the soil level after a week — top it up where it has settled below the rim.
Equip the job
Hand-picked categories that match the shopping list above. Links open a current selection so you can compare brands and prices.
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Keep planning
Garden & Yard
Answers
Multiply length × width × height (in feet) to get cubic feet, then divide by 27 for cubic yards. A 4×8 bed 12 inches deep needs about 1.2 cubic yards — roughly 21 bags of 1.5 cubic foot mix. The planner does this for you and switches to bulk pricing once you pass a cubic yard, where buying in bulk gets much cheaper.
Cedar is the default: naturally rot-resistant, and a 2×6 cedar bed typically lasts 10–15 years. Untreated fir or pine costs about half as much and gives you three to six seasons before the bottom board softens. Composite never rots but flexes, so it wants a post or bracket every 4 feet. On pressure-treated: the arsenic-based CCA people still worry about was pulled from residential sale in 2003. Today's copper azole and ACQ lumber leaches small amounts of copper into the first inch of soil, and most extension services rate it acceptable for edibles. If you'd still rather not, staple a fabric or poly liner to the inside faces.
Six inches is plenty for lettuce, spinach and herbs if the native soil below is decent and roots can push into it. Twelve inches is the sweet spot for most vegetables — tomatoes, peppers, beans — and it drains well without a lot of fill. Go 18–24 inches for carrots and other root crops, over compacted clay or a patio slab, or to garden without kneeling. Watch what that costs: taking a 4×8 bed from 12 to 24 inches roughly doubles the fill, from about 1.2 to 2.4 cubic yards, and soil is usually the biggest line on the receipt. Fill the bottom third of a tall bed with logs and coarse chips to cut it.
Leave the bottom open in almost every case — roots reach into the native soil, water drains away instead of pooling, and worms work their way up into the bed. A fabric liner stapled to the inside faces slows rot and keeps weeds out of the board seams; it's worth doing on pine, less so on cedar. Half-inch hardware cloth across the base is the one add-on that earns its keep if you have gophers or voles, since they can strip a bed of root crops from underneath in a night. Never lay solid plastic on the bottom — it traps water and drowns roots.