How much lumber for a raised bed? Board count by bed size

Quick answer: a 4 x 8 ft raised bed takes three 8 ft 2x6 boards for one board high (5 1/2 in) or six boards for two boards high (11 in). Add one 8 ft 4x4, cut into six posts, and 20 exterior screws for one board high or 40 for two. The charts below give the board count, cut list, posts and screws for other common sizes and board widths, and every row opens the full plan in our planner.

8 ft 2x6 boards to buy for common bed sizes:

2 x 4 ft: 2 boards one 2x6 high, 4 boards two high
3 x 6 ft: 3 boards one 2x6 high, 6 boards two high
4 x 4 ft: 2 boards one 2x6 high, 4 boards two high
4 x 8 ft: 3 boards one 2x6 high, 6 boards two high
4 x 12 ft: 4 boards one 2x6 high, 8 boards two high

Have a different size? The free raised bed lumber calculator on our planner handles any size, L-shaped beds and several beds at once. It packs every cut onto the fewest boards, compares 8, 10 and 12 ft boards, and adds soil and cost.

One 2x6 board high (5 1/2 in)

All charts use the planner's default build: cedar boards, 8 ft long, with 4x4 posts in the corners. Long boards run the full length of the bed, and end boards fit between them. Bed sizes are outside measurements.

Lumber for a raised bed one 2x6 high
Bed size (outside)	8 ft 2x6 boards to buy	How to cut them	4x4 posts	3 in screws	Lumber, posts and screws (cedar)	Other board lengths
2 x 4 ft	2	1 cut into 4 ft + 1 ft 9 in + 1 ft 9 in; 1 cut into 4 ft	4 at 5 1/2 in, from 1 x 8 ft 4x4	16	about $86	1 x 12 ft board saves about $11
3 x 6 ft	3	2 cut into 6 ft; 1 cut into 2 ft 9 in + 2 ft 9 in	4 at 5 1/2 in, from 1 x 8 ft 4x4	16	about $108	2 x 10 ft boards save about $11
4 x 4 ft	2	2 cut into 4 ft + 3 ft 9 in	4 at 5 1/2 in, from 1 x 8 ft 4x4	16	about $86	8 ft costs the same or less
4 x 8 ft	3	2 whole; 1 cut into 3 ft 9 in + 3 ft 9 in	6 at 5 1/2 in, from 1 x 8 ft 4x4	20	about $108	8 ft costs the same or less
4 x 12 ft	4	2 whole; 2 cut into 4 ft + 3 ft 9 in	8 at 5 1/2 in, from 1 x 8 ft 4x4	28	about $130	8 ft costs the same or less

A bed one board high holds only about 4 1/2 in of soil. University of Missouri Extension says most plants need at least a 6 to 12 in rooting zone, so a bed this shallow works best on top of loosened ground, where roots can grow down into the soil below.

Two 2x6 boards high (11 in)

This is the most common first bed. It holds about 10 in of soil.

Lumber for a raised bed two 2x6 boards high
Bed size (outside)	8 ft 2x6 boards to buy	How to cut them	4x4 posts	3 in screws	Lumber, posts and screws (cedar)	Other board lengths
2 x 4 ft	4	2 cut into 4 ft + 1 ft 9 in + 1 ft 9 in; 2 cut into 4 ft	4 at 11 in, from 1 x 8 ft 4x4	32	about $130	2 x 12 ft boards save about $22
3 x 6 ft	6	4 cut into 6 ft; 2 cut into 2 ft 9 in + 2 ft 9 in	4 at 11 in, from 1 x 8 ft 4x4	32	about $174	4 x 10 ft boards save about $22
4 x 4 ft	4	4 cut into 4 ft + 3 ft 9 in	4 at 11 in, from 1 x 8 ft 4x4	32	about $130	8 ft costs the same or less
4 x 8 ft	6	4 whole; 2 cut into 3 ft 9 in + 3 ft 9 in	6 at 11 in, from 1 x 8 ft 4x4	40	about $174	8 ft costs the same or less
4 x 12 ft	8	4 whole; 4 cut into 4 ft + 3 ft 9 in	8 at 11 in, from 1 x 8 ft 4x4	56	about $230	8 ft costs the same or less

Two 2x8 boards high (14 1/2 in)

A 2x8 is really 7 1/4 in wide, so two of them make a 14 1/2 in wall with the same board count as two 2x6.

Lumber for a raised bed two 2x8 boards high
Bed size (outside)	8 ft 2x8 boards to buy	How to cut them	4x4 posts	3 in screws	Lumber, posts and screws (cedar)	Other board lengths
2 x 4 ft	4	2 cut into 4 ft + 1 ft 9 in + 1 ft 9 in; 2 cut into 4 ft	4 at 14 1/2 in, from 1 x 8 ft 4x4	32	about $170	2 x 12 ft boards save about $32
3 x 6 ft	6	4 cut into 6 ft; 2 cut into 2 ft 9 in + 2 ft 9 in	4 at 14 1/2 in, from 1 x 8 ft 4x4	32	about $234	4 x 10 ft boards save about $32
4 x 4 ft	4	4 cut into 4 ft + 3 ft 9 in	4 at 14 1/2 in, from 1 x 8 ft 4x4	32	about $170	8 ft costs the same or less
4 x 8 ft	6	4 whole; 2 cut into 3 ft 9 in + 3 ft 9 in	6 at 14 1/2 in, from 1 x 8 ft 4x4	40	about $234	8 ft costs the same or less
4 x 12 ft	8	4 whole; 4 cut into 4 ft + 3 ft 9 in	8 at 14 1/2 in, from 2 x 8 ft 4x4	56	about $340	8 ft costs the same or less

One 2x10 board high (9 1/4 in)

One wide board means half as many boards as two 2x6, for a slightly lower wall. Boards wider than 8 in get three screws per board end.

Lumber for a raised bed one 2x10 high
Bed size (outside)	8 ft 2x10 boards to buy	How to cut them	4x4 posts	3 in screws	Lumber, posts and screws (cedar)	Other board lengths
2 x 4 ft	2	1 cut into 4 ft + 1 ft 9 in + 1 ft 9 in; 1 cut into 4 ft	4 at 9 1/4 in, from 1 x 8 ft 4x4	24	about $126	1 x 12 ft board saves about $21
3 x 6 ft	3	2 cut into 6 ft; 1 cut into 2 ft 9 in + 2 ft 9 in	4 at 9 1/4 in, from 1 x 8 ft 4x4	24	about $168	2 x 10 ft boards save about $21
4 x 4 ft	2	2 cut into 4 ft + 3 ft 9 in	4 at 9 1/4 in, from 1 x 8 ft 4x4	24	about $126	8 ft costs the same or less
4 x 8 ft	3	2 whole; 1 cut into 3 ft 9 in + 3 ft 9 in	6 at 9 1/4 in, from 1 x 8 ft 4x4	30	about $168	8 ft costs the same or less
4 x 12 ft	4	2 whole; 2 cut into 4 ft + 3 ft 9 in	8 at 9 1/4 in, from 1 x 8 ft 4x4	42	about $210	8 ft costs the same or less

Costs use the planner's default cedar prices: $22 per 8 ft 2x6, $32 per 2x8, $42 per 2x10, $30 per 8 ft 4x4 and $12 per box of about 50 screws. Longer boards are priced by length. These are typical US big-box prices and vary by region and season, so edit them in the planner to match your store.

How we count the boards

Nominal vs actual size. A 2x6 is really 1 1/2 in thick and 5 1/2 in wide. A 2x8 is 7 1/4 in wide and a 2x10 is 9 1/4 in.
End boards fit between the long boards, so they are 3 in shorter than the outside width. That keeps the outside size exact.
Mid-wall posts. Walls longer than 6 ft get a post about every 4 ft to stop them bowing when the bed is full of wet soil. A 4 x 8 ft bed has 6 posts and a 4 x 12 ft bed has 8.
Joints land on posts. When a wall is longer than your boards, the planner joins the pieces at a mid-wall post.
Fewest boards. Cuts are packed onto the fewest boards, with 1/8 in allowed for each saw cut.
Screws. Two 3 in exterior screws per board end (three for boards wider than 8 in), plus the same number where a board runs past a mid-wall post.

Which wood?

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, and University of Maryland Extension notes that research at Oregon State University found MCA-treated lumber raised soil copper by a minor amount and only within 1 in of the bed edge, with no increase in copper in the plants grown. 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.

Lumber, posts and screws for a 4 x 8 ft bed two 2x6 boards high, by wood
Wood	Estimated cost
Cedar	about $174
Pressure-treated pine	about $86
Untreated pine	about $72

Ready to build? Open the 4 x 8 ft plan in the planner for the board-by-board cut plan and a printable shopping list. See also our 4x8 raised bed plans with step-by-step build instructions and our soil chart.

Questions

How many 2x6 boards do I need for a 4x8 raised bed?

Using 8 ft boards: three for a bed one board high (5 1/2 in), six for two boards high (11 in) and nine for three boards high (16 1/2 in). In each row, two boards stay whole for the long sides and one board is cut into the two 3 ft 9 in end pieces.

How many boards do I need for a 4x4 raised bed?

With 8 ft 2x6 boards, two for one board high and four for two boards high. Cut each board into one 4 ft long-side piece and one 3 ft 9 in end piece.

How long should the end boards be?

The end boards fit between the long boards, so cut them 3 in shorter than the outside width of the bed (two board thicknesses of 1 1/2 in). That is 1 ft 9 in for a 2 ft wide bed, 2 ft 9 in for a 3 ft wide bed and 3 ft 9 in for a 4 ft wide bed.

Should I buy 8, 10 or 12 ft boards?

It depends on the bed size. At our default prices (longer boards priced by length), 8 ft boards cost the same or less than 10 or 12 ft boards for 4 x 4, 4 x 8 and 4 x 12 ft beds. A 2 x 4 ft bed one 2x6 high needs two 8 ft boards or just one 12 ft board, which saves about $11. A 3 x 6 ft bed two boards high needs six 8 ft boards or four 10 ft boards, which saves about $22. The planner compares all three lengths for your plan and tells you which is cheapest.

How do I build a 4x12 bed with 8 ft boards?

Each long wall is one 8 ft board plus a 4 ft piece, butted together over a mid-wall post. For a bed two 2x6 boards high that is 8 boards of 8 ft, 8 posts and 56 screws. With 12 ft boards the long walls need no joint: 6 boards and 48 screws, but at our default prices the lumber costs about $198 instead of $176.

These numbers come straight from our planner, which we test on more than 30,000 bed designs. They are estimates for planning. Lumber is not always true to size and prices change, so measure twice and check prices at your store. Spot a problem? Report it.