Seed and seedling estimates

Enter the target and the assumptions

Start with the desired final plant count. A layout can provide that target, or you can enter one directly. Germination and seedling survival are separate percentages: the second applies after germination, not to the original seed count again.

Extra reserve adds a fraction of the target before the rate adjustment: target × (1 + reserve / 100). Keep it separate from loss assumptions. If spare plants are already included in the target, adding another reserve can count that allowance twice.

Follow the example calculation

Enter 40 target plants, 80% germination, 90% survival, and 0% extra reserve. Convert the percentages to 0.8 and 0.9. Their product is 0.72, so 40 ÷ 0.72 is approximately 55.56. Rounding upward gives 56 seed units.

The estimate rounds upward once at the end. The intermediate arithmetic is not a direction to count a fraction of a seed. Neither the result nor the rounding guarantees that the target number of plants will be reached.

With the same target and rates but a 10% reserve, the numerator becomes 44 plants and the final rounded estimate is 62. A target of zero is allowed and gives zero; the target otherwise needs to be a nonnegative whole number.

Check what a seed unit means

Read the supplier’s description when the material is counted as pellets, clusters, or another unit rather than individual single-embryo seeds. A simple rate model is only useful when you understand the relationship between the unit you count and the seedlings you expect.

Use your own recorded assumptions and add a note if the result needs that qualification. Do not reuse the example’s 80% and 90% just because they are visible in an explanation; those numbers are demonstration inputs.

Correct an invalid value

Germination and survival percentages must each be greater than zero and no greater than 100, including when the target is zero. A zero rate cannot support the division used by this estimate. The field error tells you which input needs attention while the other values remain available.

1. Read the inline error beside the highlighted field.
2. Correct the percentage or target rather than accepting an infinite or stale result.
3. Update the estimate.
4. Check that the displayed inputs still match your intended assumptions.

Keep the result usable

When you save the number or use it to prepare a sowing, keep the target and percentage assumptions beside it. Recalculate if the target layout, expected rates, or reserve changes. A bare count is not enough to reconstruct the estimate later.

Use the plant count directly when your task is obtaining established seedlings rather than starting seed. The seed estimate is a planning aid for a particular workflow, not a universal shopping quantity for every way of growing the crop.