Seed rate calculator
Enter the area, the recommended seed rate and the germination of your seed lot to get the quantity to buy.
| Breakdown | Value |
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Estimate. The method and sources are on this page — check them against your own case before you act.
How it is calculated
Seed rate is the weight of seed needed to establish the right plant population on a given area. If the seed lot germinates poorly, the quantity must rise to compensate.
Base seed = area × seed rate · Seed to buy = base seed × 100 ÷ germination %
Match the rate to the crop and method
Wheat drilled at 100 kg/ha is about 40.5 kg/acre, while transplanted paddy at 40–50 kg/ha is only 16–20 kg/acre. Broadcasting usually needs more seed than line sowing.
Multiply by the area
40.5 kg/acre on 2.5 acres is 101.25 kg. Convert to hectares first if your recommendation is written in kg/ha: 1 hectare is 2.471 acres.
Adjust for germination
A lot with 80% germination needs 100 ÷ 80 = 1.25 times the base seed. A 90% lot needs 1.11 times. The calculator does this adjustment and shows the extra seed.
Seed rates used in this calculator
| Crop and method | Seed rate (kg/ha) | Approx. kg/acre | Note |
|---|---|---|---|
| Wheat — seed drill | 100 | 40.5 | Rabi crop. Broadcasting wheat needs about 300 kg/ha. |
| Paddy — transplanting | 40–50 | 16–20 | 50 kg/ha for thick-grained, 40 for thin-grained varieties. |
| Paddy — line sowing / direct seeded | 80–90 | 32–36 | Broadcast (biasi) paddy uses 100–120 kg/ha. |
| Maize — normal hybrid | 17.5–20 | 7–8 | Sweetcorn 7.5–10 kg/ha; baby corn 25 kg/ha. |
| Bt cotton hybrid | 2.1 | 0.9 | Only 2.125 kg/ha because of high seed cost and precision sowing. |
| American cotton varieties | 15–20 | 6–8 | Open-pollinated varieties need much more seed than hybrids. |
| Moong (green gram) | 20–25 | 8–10 | Sow at the onset of the monsoon, 30 × 10 cm spacing. |
| Bajra | 4 | 1.6 | Advisory states 1.6 kg/acre at 45 × 15 cm spacing. |
| Jowar — grain purpose | 12–15 | 5–6 | Fodder jowar uses a different rate. |
What most pages get wrong
Seed rate is per area, not per plant
Recommendations are written as kg per hectare or per acre because that is what a farmer buys. Plant population and spacing are already built into the rate.
Poor germination is a hidden cost
Sowing a 70% germination lot at the normal rate leaves gaps in the field. The calculator increases the quantity so the plant stand matches the recommendation.
1 hectare is 2.471 acres
Most official seed rates are in kg/ha while Indian farmers often buy by the acre. Divide the kg/ha figure by 2.471 to get kg/acre.
More seed is not more yield
Over-seeding wastes seed and can reduce yield through competition, lodging and disease. Stick close to the recommendation for your variety and spacing.
Frequently asked questions
How much wheat seed do I need for 1 acre?+
Should I increase seed if germination is low?+
How do I convert a kg/hectare recommendation to kg/acre?+
How much paddy seed is needed for 1 acre?+
Does spacing change the seed rate?+
Is a higher seed rate safer?+
Sources, dates and a changelog.
Every number this calculator uses is either an input you control or a value from the sources below. The formula is compiled and tested at build time, so the page cannot ship with a broken calculation.
Sources
This page
- Last verified: 29 October 2026
- Next review: 29 April 2027
- Vertical: Agriculture & Farming
- Build tests: 3 passed
- Changelog: 1 entry
How we handle errors
- Spotted a mistake? Report it — we correct and log it.
- Corrections appear in the changelog below.
- Read the methodology and the disclaimer.