Row Spacing: A Worked Guide to Rows Per Bed

Row spacing is the distance between one row of vegetables and the next row in a bed, and this guide works row spacing step by step with the page formula and the page worked examples.

What row spacing means

Row spacing runs across the bed, from the centre of one row to the centre of the next row. The number of rows depends on the bed width, the row spacing, and the margin left at each edge. The total row length is rows times bed length, and it is the length you have to mark out and sow. Row spacing is not the distance between plants along a row, and this calculator does not use that distance.

The page formula step by step

First find the usable width, then find how many rows fit, then find the total row length.

Step 1: usable width equals bed width minus 2 times margin. The margin is taken off twice, once at the first edge and once at the far edge.

Step 2: rows equals floor of usable width divided by spacing, plus 1. Floor division means divide, then drop any fraction. The plus 1 needs a plain explanation. The first row sits one margin in from the first edge, and the last row sits one margin in from the far edge, so the rows are one more than the gaps between them.

Step 3: total row length equals rows times bed length. The Row Spacing Calculator shows the rows, the spacing, and the total row length.

Worked example 1: metric, a 1.2 m bed

The page metric example is a bed 1.2 m wide and 3 m long, with 15 cm margins and 30 cm row spacing. Use centimetres throughout, so 1.2 m is 120 cm.

Usable width equals 120 minus 2 times 15, which is 90 cm. Rows equals floor of 90 divided by 30, plus 1, which is 4. Total row length equals 4 times 3, which is 12 m. So the bed fits 4 rows, and on a 3 m bed that is 12 m of row to sow.

Worked example 2: imperial, a 4 ft bed

The page imperial example is a bed 4 ft wide and 10 ft long, with 6 in margins and 12 in row spacing, so use inches throughout.

Usable width equals 48 minus 2 times 6, which is 36 in. Rows equals floor of 36 divided by 12, plus 1, which is 4. Total row length equals 4 times 10, which is 40 ft. So the bed fits 4 rows, and on a 10 ft bed that is 40 ft of row to sow.

Keep the two examples separate. The defaults are rounded equivalents, not exact conversions. Spacing of 30 cm is 11.81 in, not 12 in, and a margin of 15 cm is 5.91 in, not 6 in.

The standard bed at a glance

The table below uses a fixed 15 cm margin. As the bed gets wider by 30 cm, one more row fits.

Bed width	Usable width	Rows	Total row length
0.6 m	30 cm	2	6 m
0.9 m	60 cm	3	9 m
1.2 m	90 cm	4	12 m
1.5 m	120 cm	5	15 m
1.8 m	150 cm	6	18 m

A second bed size: 1.8 m and 6 ft

In metric, the bed is 1.8 m wide and 3 m long, with 15 cm margins and 30 cm row spacing. Usable width equals 180 minus 2 times 15, which is 150 cm. Rows equals floor of 150 divided by 30, plus 1, which is 6. Total row length equals 6 times 3, which is 18 m. So a 1.8 m wide bed at 30 cm spacing with 15 cm margins fits 6 rows, and on a 3 m bed that is 18 m of row to sow.

In imperial, the bed is 6 ft wide and 10 ft long, with 6 in margins and 12 in row spacing. Usable width equals 72 minus 2 times 6, which is 60 in. Rows equals floor of 60 divided by 12, plus 1, which is 6. Total row length equals 6 times 10, which is 60 ft. So a 6 ft wide bed at 12 in spacing with 6 in margins fits 6 rows, and on a 10 ft bed that is 60 ft of row to sow.

The table below uses a fixed 6 in margin.

Bed width	Usable width	Rows	Total row length
2 ft	12 in	2	20 ft
3 ft	24 in	3	30 ft
4 ft	36 in	4	40 ft
5 ft	48 in	5	50 ft
6 ft	60 in	6	60 ft

How to use the calculator

First, enter bed width and length. Second, choose to set spacing or number of rows. Third, enter the spacing or row count. Fourth, set a margin from each edge, often half the row spacing. Fifth, mark rows with string before sowing.

Set spacing mode finds rows from a spacing, and set row count mode finds spacing from a row count, using spacing equals usable width divided by rows minus 1.

Work one reverse example in metric. A 1.2 m bed with a 15 cm margin has a usable width of 90 cm. For 5 rows, spacing equals 90 divided by 4, which is 22.5 cm, and for 3 rows it is 45 cm. In imperial, the usable width is 36 in. For 5 rows, spacing equals 36 divided by 4, which is 9 in, and for 3 rows it is 18 in. One row is the single centre row case, and the formula cannot give a spacing for it, because rows minus 1 is zero.

The half spacing margin rule

The page rule is that half the row spacing is a natural edge margin, so outer plants get the same room as inner plants. At 30 cm spacing the half spacing margin is 15 cm, and at 12 in spacing it is 6 in.

The two rules can give different answers for the same spacing. At 45 cm spacing, a fixed 15 cm margin gives 3 rows on a 1.2 m bed, while a half spacing margin of 22.5 cm gives 2 rows. At 90 cm spacing, the fixed margin gives 2 rows, while the half spacing margin of 45 cm gives 1 row, the single centre row case. The half spacing rule is the page recommended rule, and the fixed 15 cm margin is the page default margin.

A margin of 0 is allowed by the calculator, and it still uses the plus one. On a 1.2 m bed at 30 cm spacing, a margin of 0 gives 5 rows, but the page guidance discourages it, because plants right at the edge dry out and spill onto paths. A margin must stay below half the bed width.

Row spacing by crop size

The page FAQ gives one spacing band by crop size. Small crops such as carrots and lettuce use 30 cm (12 in) between rows. Larger crops use 45 to 90 cm (18 to 36 in) between rows. That band is a starting point to edit, not a universal constant.

At 30 cm the count is 4 rows, as worked above. At 45 cm the count is 3 rows and 9 m of row, at 60 cm it is 2 rows and 6 m, and at 90 cm it is 2 rows and 6 m, all on a 3 m bed with the same fixed 15 cm margin. Those counts use the fixed margin.

What the calculator does not give

The calculator gives rows, spacing, and total row length only, from bed width, bed length, row spacing or row count, and an edge margin. It does not give plants per row, plants per bed, a density figure, a seed count, a yield figure, or a cost figure. Total row length does not tell you how many plants will stand in that row, because the calculator never asks for the distance between plants along a row.

The page assumptions

Wide crops may need a single centre row. Paths between beds are not included, so measure the bed itself, not the bed plus its path. Direct sown rows can be closer than transplant rows. Rows often run north to south, for even sun on both sides of the row through the day.

The Crop Spacing Calculator covers plants per bed from two spacings, the Plant Spacing Calculator covers a single spacing, the Garden Bed and Path Layout Calculator covers bed and path layout, and the Garden Area Calculator covers measuring the garden area.

Frequently asked questions

Q: What is row spacing?

A: Row spacing is the distance between one row and the next row across a bed, measured from the centre of one row to the centre of the next row.

Q: How many rows fit a 1.2 m bed at 30 cm spacing?

A: 4 rows, with 15 cm margins and 12 m of row on a 3 m bed.

Q: How many rows fit a 4 ft bed at 12 in spacing?

A: 4 rows, with 6 in margins and 40 ft of row on a 10 ft bed.

Q: What margin should I leave at the edge of a bed?

A: Often half the row spacing, so outer plants get the same room as inner plants. At 30 cm spacing that margin is 15 cm.

Q: How far apart should vegetable rows be?

A: 30 cm (12 in) for small crops such as carrots and lettuce, and 45 to 90 cm (18 to 36 in) for larger crops.

Q: Should rows run north to south?

A: Often yes, it gives both sides of the row even sun through the day.