Raised Bed Builder

Plan your raised garden bed, board by board.

Enter your bed size. Get a shopping list, a lumber cut list, soil in bags or bulk, and a cost estimate. Free, no sign-up.

  • Rectangle and L-shaped beds
  • Many beds at once
  • Bags vs bulk soil
  • Metric or imperial
Start planning
Illustrated wooden raised bed full of tomatoes, lettuce, carrots and radishes, with a watering can, a trowel and a bright sun

Your beds

Measure the outside edges of each bed. Add as many beds as you like, in any mix of sizes.

Walls

Soil

Extras

See my plan

Build with confidence. Our calculator has been tested on more than 30,000 bed designs, with every result double-checked by a separate calculator.
Even so, no tool is perfect, so measure twice and check prices at your store.How we test Full disclaimer Report a problem

Shopping list

Everything for every bed in one list. Check items off at the store.

Lumber and cut list

Posts, brackets and screws

Soil and mix

Liner, hardware cloth and drip

Cost estimate

Top view

What fits in your beds

Square foot spacing, based on common extension service guidance. Enter how many 1 ft squares you want for each crop.

Something look wrong?

If a number, cut or count seems off, tell us and we will check it and fix it.

This month in the garden

How to build a raised garden bed

  1. Pick the spot. Most vegetables need 6 to 8 hours of direct sun. Choose level ground close to a hose. Keep beds 4 ft wide or less so you can reach the middle from either side.
  2. Cut your boards. Use the cut list above. Long walls run full length, and the end walls fit between them, so end boards are 3 in shorter than the bed's outside width. Wear a dust mask when cutting, and seal cut ends of treated boards with an end-cut preservative.
  3. Assemble the walls. Stand a 4x4 post inside each corner and drive two 3 in exterior screws (three for 2x10 and 2x12 boards) through each board end into the post. Pre-drill near board ends to avoid splits. Walls over 6 ft get mid-wall posts, and any joint between two boards is centered on one. Build one row at a time and check for square by measuring both diagonals.
  4. Protect the bottom. If gophers or voles are a problem, staple 1/2 in hardware cloth across the bottom and 6 in up the walls. On grass, a layer of plain cardboard smothers the turf.
  5. Fill and water. Mix your soil on a tarp or in the bed, water it well, and let it settle a few days. Top it up to about 1 in below the rim before you plant.
Illustrated gardener harvesting fresh vegetables from a finished raised bed

How deep should a raised bed be?

Lettuce, spinach, herbs and radishes do well in 6 to 8 in of soil. Tomatoes, peppers, beans and squash prefer 10 to 12 in. Carrots, parsnips and potatoes like 12 to 18 in. If your bed sits on concrete or a patio, add a few inches since roots cannot reach the ground below.

Choosing lumber and soil

Illustrated stack of cedar boards with a hand saw, tape measure and screws

Which wood lasts?

Cedar and redwood resist rot on their own and often last 10 years or more, depending on climate. Pressure-treated pine sold for homes since 2004 uses copper-based preservatives (ACQ, CA or MCA), and many extension services consider it acceptable for food gardens. Buy boards rated for ground contact, and line the inside walls if you would rather keep soil off the wood. Treated wood is not allowed in certified organic growing. Avoid old CCA lumber and railroad ties. Untreated pine is cheapest but may need replacing in 3 to 5 years.

Illustrated soil cross-section showing layers of topsoil and compost with carrots, potatoes and earthworms

Which soil mix?

The classic 60/30/10 blend of topsoil, compost and an aerator like perlite is affordable and holds moisture well. Mel's Mix, from the Square Foot Gardening method, is lighter and drains fast but costs more. A 50/50 topsoil and compost blend is a simple middle ground.

Illustrated drip line watering plants in a raised bed lined with hardware cloth

Why drip irrigation?

Raised beds dry out faster than the ground. Drip line puts water at the roots, keeps leaves dry to reduce disease, and uses less water than a sprinkler. Run lines about 12 in apart and add a timer for steady watering.

More guides: How much soil for a raised bed (chart by bed size) and 4x8 raised bed plans with a cut list.

Raised bed questions

How much soil does a 4x8 raised bed need?

A 4 by 8 ft bed (measured outside) built from 1.5 in thick boards is about 3 ft 9 in by 7 ft 9 in inside. Filled 10 in deep, with the six 4x4 posts taken out, that holds about 23.8 cubic feet. With 10% extra for settling, plan on about 26.2 cubic feet (about 0.97 cubic yards), or about 19 bags of 1.5 cu ft in the classic 60/30/10 mix: 11 topsoil, 6 compost and 2 perlite or potting mix.

Why is my cut list different from just measuring the walls?

Lumber is sold by nominal size. A 2x6 is really 1.5 in thick and 5.5 in wide. Because the end boards fit between the long boards, they are cut 3 in shorter. The planner also packs cuts onto the fewest boards and allows 1/8 in for each saw cut.

Is it cheaper to buy soil in bags or bulk?

For one small bed, bags usually win. Bulk delivery usually becomes cheaper somewhere around 1 to 2 cubic yards, even after the delivery fee. At our default prices, one 4x8 bed (about 1 cubic yard) already comes out a little cheaper in bulk. The planner compares both using prices you can edit.

Do I need corner posts or brackets?

Either works. 4x4 posts are cheap and sturdy. Metal brackets are quick to install and make beds easy to take apart. Walls longer than 6 ft benefit from a mid-wall post to stop bowing once the bed is full. The planner adds one about every 4 ft and lines up board joints on them.

Should I put anything under a raised bed?

Hardware cloth stops burrowing pests. Cardboard smothers grass and breaks down in a season. Avoid plastic sheeting under the soil because it blocks drainage.

How do I share or save my plan?

Your plan is saved in the page address as you type. Use "Share plan link" or bookmark the page to come back to it. Nothing is stored on our servers.