Free seed spacing calculator. Enter row length and seed spacing to find how many seeds fit in one garden row, with one seed at each end.
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Enter row length and seed spacing in centimetres. The calculator divides row length by spacing, rounds down to whole seeds, then adds one seed for the start of the row. Use the vegetable seed spacing chart below to pick a spacing, and add a germination buffer when you buy seed packets.
Seeds per row equal floor of row length divided by spacing, plus one. The plus one counts the seed at the very start of the row. A 300 centimetre row at 15 centimetre spacing gives floor of 300 divided by 15, which is 20, plus one, which is 21 seeds. Without the plus one the row would wrongly show 20 seeds and the last spacing step would have no seed at its end.
In row spacing is the distance between seeds along one row, and it decides how many seeds fit in that row. Row spacing is the distance between parallel rows, and it decides how many rows fit in a bed, not how many seeds go in one row. Competitor guides keep the two apart for good reason: mixing them up either crowds a row or wastes bed space. This calculator works with in row spacing only.
Use these spacing guides in inches as a starting point, then check your seed packet for the exact variety. Carrots suit 2 inches apart, radishes 1 inch, peas 2 to 3 inches, beans 3 to 4 inches, lettuce 6 to 12 inches, cucumbers 12 to 18 inches, peppers 12 to 24 inches, and tomatoes 18 to 24 inches in a row. Convert inches to centimetres by multiplying by 2.54 before you enter a value here.
Germination is never perfect, so competitor calculators add a germination buffer of 10 to 20 percent to the seeds to plant, giving seeds to buy. Fresh seed from a good supplier suits a 10 to 15 percent buffer, while old seed or cold soil suits 20 to 25 percent. Divide seeds to buy by seeds per packet and round up to whole packets, since packets hold very different counts: a tomato packet may hold 25 seeds while a carrot packet may hold 500.
Some crops are almost always direct sowed: carrots, beets, radishes, peas and beans grow best sown straight in the garden. Others, like tomatoes, peppers, eggplant, broccoli and celery, are usually started indoors and moved out as seedlings. Seedling spacing is wider than seed spacing for those crops, because seedlings are thinned and spaced before they go in the ground. If you transplant, plan with seedling counts and wider spacing instead of this row seed count.
Sowing a few extra seeds is normal, but thinning seedlings to the planned spacing is what gives each plant room to grow. Thin when seedlings show true leaves, keeping the strongest plant in each spot and snipping the rest at soil level rather than pulling them, so you do not disturb the roots of the plant you keep. Crowded rows stay small, shade each other, and invite disease.
Take a 10 foot row, which is about 305 centimetres, at 15 centimetre spacing. Floor of 305 divided by 15 is 20, plus one is 21 seeds for the row. At that spacing the row holds about 2 seeds per foot. A 300 centimetre row at 30 centimetre spacing holds floor of 300 divided by 30, which is 10, plus one, which is 11 seeds, showing how wider spacing cuts the count fast.
Divide row length by seed spacing, round down, and add one for the starting seed. A 300 centimetre row at 15 centimetre spacing fits 21 seeds.
Because the first seed sits at the start of the row, before the first spacing step. Without it, the last step of the row would have no seed.
In row spacing is the gap between seeds along a row. Row spacing is the gap between rows. Only in row spacing changes the seed count per row.
It depends on spacing. At 15 centimetres, about 6 inches, a row holds about 2 seeds per foot. At 30 centimetres it holds about 1 seed per foot.
Yes. Add a germination buffer of 10 to 20 percent to your seeds to plant count, more for old seed or cold soil, then round up to whole packets.
Divide seeds to buy by the packet size and round up. Always check the packet count, since it varies widely by crop.
Direct sow root crops like carrots and radishes. Start tomatoes, peppers, eggplant, broccoli and celery indoors and transplant them as seedlings.
Thin once true leaves appear, keeping the strongest seedling in each spot and snipping the rest at soil level.
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