Agricultural Field Calculators
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Seed Rate Calculator — Seeds Per Acre, Bags & Seed Cost

Calculate planting population, seed spacing, and sacks to order for corn, soybeans, dry beans, wheat, sunflowers, and other row crops. The Potato Seed tab handles seed piece weight, chip loss, and full cost estimation. Fully reversible — enter population to calculate spacing, or enter spacing to calculate population.

Calculate planting population, seed spacing, and the number of seed bags needed to order for any field size. Supports corn, soybeans, wheat, canola, and other row and small-grain crops. Enter your target seeds per acre, expected germination rate, row spacing, and field size — get seeds per foot of row, bags required, and total seed cost. Useful for seed ordering, planting population audits, and agronomic planning. Works in acres and hectares.

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Seed Rate Calculator

Population ↔ spacing ↔ sacks to order. Switch tabs for grain seed or potato seed.

Units
Area
▶ calculated
Presets:
▶ calculated
Field & Sack Size
Enter to calculate kg/ha seeding rate. Corn ≈ 0.28–0.35 g  ·  Soybeans ≈ 0.17–0.22 g  ·  Wheat ≈ 0.03–0.05 g
Spacing Units
Planting Specs
Cost Inputs (optional)

Fill in the fields to see your results.

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📊 Related calculators: Fertilizer Rate — calculate starter fertilizer rates alongside your seeding pass.  |  GDD Tracker — track heat unit accumulation from your planting date automatically.  |  Crop Yield — project revenue at expected yield and price.

Disclaimer — Seed rate calculations are estimates based on standard germination and emergence assumptions. Actual emergence varies with soil conditions, planting depth, temperature, and seed lot quality. Consult your seed dealer and agronomist for field-specific seeding rate recommendations. For starter fertilizer and chemical rates, use the Fertilizer Rate Calculator.

Frequently Asked Questions

Seeding rate is the number of seeds planted per unit of land area — typically expressed as seeds per acre or seeds per hectare. It's distinct from the seed bag label's "seeds per pound" or "seeds per unit." The optimal seeding rate depends on the crop, target plant population, expected germination rate, and row spacing. Planting too few seeds reduces yield; planting too many wastes seed cost without yield benefit. This calculator converts between seeding rate, field size, and the number of seed bags needed to order.

Seeds per acre = target plant population. Most corn plants at 28,000–34,000 seeds/acre. Bags needed = (acres × seeds/acre) ÷ seeds per bag. Standard corn bags contain 80,000 seeds — one bag plants approximately 2.5–2.9 acres.
Winter wheat: 60–100 lbs/acre depending on variety, planting date, and seedbed conditions. Earlier planting (before October 1): 60–75 lbs/acre. Late planting after October 15: 90–110 lbs/acre.
Seed pieces/acre = 43,560 ÷ (row spacing ft × in-row spacing ft). At 36-inch rows and 9-inch in-row spacing: 43,560 ÷ (3 × 0.75) = 19,360 pieces/acre. At 2 oz average piece weight: 19,360 × 0.125 lbs = 2,420 lbs/acre seed.
Optimal Russet Burbank seed piece: 2.0–2.5 oz (57–71 g) with at least 2 eyes. Pieces below 1.5 oz increase disease risk; above 3 oz offer diminishing returns. Blocking to uniform size reduces variability in emergence and plant spacing.
Adjusted seeding rate = target plants/acre ÷ germination fraction. At 94% germination targeting 30,000 plants/acre: 30,000 ÷ 0.94 = 31,915 seeds/acre needed. The calculator includes a germination percentage adjustment.
Russet Burbank: 9–10 inches. Clearwater Russet: 10–12 inches (wider for better size profile). Ranger Russet: 9–10 inches. Umatilla Russet: 9–10 inches. Russet Norkotah: 10–12 inches. Mountain Gem Russet: 10–12 inches. All at standard 36-inch rows.

Seeds per acre = (lbs/acre seed rate × seeds/lb). For corn at 34,000 plants/acre with 94% germination, you need 34,000 ÷ 0.94 = 36,170 seeds/acre. At 80,000 seeds/unit, that is 36,170 ÷ 80,000 = 0.452 units/acre. The seed rate calculator handles this conversion automatically for corn, soybeans, wheat, and other crops.

Corn seeding rates typically run 30,000–36,000 seeds/acre for dryland and 32,000–38,000 seeds/acre for irrigated production, adjusted for hybrid, soil, and irrigation capability. Higher plant populations (38,000+) are sometimes used on high-yield irrigated ground but require careful hybrid selection to avoid barrenness and stalk rot.