How much grass seed do I need?
Divide the lawn area by 1,000 and multiply by the seeding rate for your grass, in pounds per 1,000 square feet.
pounds of seed = square feet ÷ 1,000 × seeding rate
A 50 × 40 ft lawn is 2,000 sq ft. Turf-type tall fescue is seeded at 6–8 lb per 1,000 sq ft,[1] so it needs 2 × 6 to 2 × 8 = 12–16 lb. The same lawn in Kentucky bluegrass, at 2–3 lb, needs 4–6 lb.[1] Measure odd shapes with the irregular area guide or the square yard calculator.
Seeding rates by grass type
Rates differ several-fold between grasses: tall fescue is sown at roughly three times the weight of Kentucky bluegrass. Rates for a new lawn:
| Grass | lb per 1,000 sq ft | g per m² | Source |
|---|---|---|---|
| Turf-type tall fescue | 6–8 | 29.3–39.1 | [1] |
| Kentucky bluegrass | 2–3 | 9.8–14.6 | [1] |
| Kentucky bluegrass 80–90% + perennial ryegrass 10–20% | 3–4 | 14.6–19.5 | [1] |
| Kentucky bluegrass + fine fescue + perennial ryegrass mix | 3–4 | 14.6–19.5 | [1] |
| Turf-type perennial ryegrass | 4–5 | 19.5–24.4 | [1] |
| Fine fescues | 4–5 | 19.5–24.4 | [1] |
| Shade mix: fine fescue, bluegrass, ryegrass | 4 | 20 | [1] |
| Rough bluegrass (wet shade) | 2–3 | 9.8–14.6 | [1] |
| Common bermudagrass | 1–2 | 4.9–9.8 | [2] |
| Zoysiagrass (seeded cultivars) | 1–2 | 4.9–9.8 | [2] |
| Centipedegrass | 0.25–0.5 | 1.2–2.4 | [2] |
Cool-season rates are from Penn State Extension; warm-season rates are from NC State Extension, which notes that many coated bermudagrass seeds need a higher rate and that only a few zoysiagrass cultivars are sold as seed.[1][2] Rates differ a little between universities; NC State, for example, uses 6 lb for tall fescue and 1–2 lb for Kentucky bluegrass alone.[2] Follow the rate on your seed label when it differs.
How much seed to overseed a lawn?
Use 25–50% less than the new-lawn rate when seeding into existing grass. NC State Extension says that when seeding into existing vegetation, "a 25 to 50 percent lower seeding rate may be appropriate", and to use the full new-establishment rate otherwise.[2] Choose Seeding into existing grass in the calculator to apply it.
Grass seed per acre, per square foot and per square meter
Multiply the rate per 1,000 sq ft by 43.56 for an acre: Penn State's own guide says to multiply by 43.[1] Tall fescue at 6–8 lb is about 261–348 lb per acre. Per square foot, divide by 1,000: 6–8 lb is 0.006–0.008 lb, about 2.7–3.6 g, per sq ft. In metric, 1 lb per 1,000 sq ft equals 4.88 g per m², from the exact definitions of the pound and the foot.[4]
Seed needs soilPenn State recommends at least 4–6 inches of good topsoil, firmed, before seeding a new lawn.[3] Size that layer with the topsoil calculator, or see how much topsoil you need.
Frequently asked questions
How much grass seed do I need for 1,000 square feet?
2–3 lb of Kentucky bluegrass, 4–5 lb of perennial ryegrass or fine fescue, or 6–8 lb of turf-type tall fescue.[1]
How much grass seed for 5,000 square feet?
30–40 lb of tall fescue or 10–15 lb of Kentucky bluegrass for a new lawn.
How much grass seed per acre?
Multiply the rate per 1,000 sq ft by 43.56. Tall fescue at 6–8 lb works out to about 261–348 lb per acre.
How much seed do I need to overseed?
Roughly 25–50% less than for a new lawn.[2]