Seeding rates (lb of seed per 1,000 sq ft)
| Grass | Season | New lawn | Overseeding |
|---|---|---|---|
| Tall fescue | Cool | 6–9 (use 7.5) | 4–6 (use 5) |
| Kentucky bluegrass | Cool | 2–3 (use 2.5) | 1–2 (use 1.5) |
| Perennial ryegrass | Cool | 3–6 (use 4.5) | 2–4 (use 3) |
| Fine fescue | Cool | 4–5 (use 4.5) | 2–3 (use 2.5) |
| Bermuda (hulled) | Warm | 0.5–2 (use 1) | 0.5–1 (use 0.75) |
| Zoysia (seeded) | Warm | 1–3 (use 2) | 0.5–1.5 (use 1) |
| Centipede | Warm | 0.25–0.5 (use 0.4) | 0.2–0.4 (use 0.25) |
The calculator uses the “use” value, the middle of the published range, which sits below the top of the range on purpose. Heavier seeding does not make a thicker lawn: seedlings crowd each other and disease risk rises.
Pounds needed by lawn size (new lawn, mid-range rate)
| Lawn size (sq ft) | Tall fescue (lb) | Kentucky bluegrass (lb) |
|---|---|---|
| 500 | 3.8 | 1.2 |
| 1,000 | 7.5 | 2.5 |
| 2,500 | 18.8 | 6.2 |
| 5,000 | 37.5 | 12.5 |
| 10,000 | 75.0 | 25.0 |
| 43,560 (1 acre) | 326.7 | 108.9 |
How to use the numbers
- Measure the area in square feet (length × width; subtract the house and beds). One acre is 43,560 sq ft.
- Multiply by the rate ÷ 1,000: 5,000 sq ft × 7.5 ÷ 1,000 = 37.5 lb of tall fescue.
- Check your seed bag. If it gives its own rate per 1,000 sq ft, use it, especially for coated seed or mixes.
- Round up to bag sizes (commonly 3, 7, 20 and 50 lb). The grass seed calculator shows the count for every size.
New lawn vs overseeding
A new lawn is bare, prepared soil, so you seed at the full rate and cover lightly with ¼ in of soil or straw. Overseeding thickens a thin lawn by seeding into the existing turf at roughly half to two-thirds of the new rate, after mowing short and dethatching or core-aerating for seed-to-soil contact. Fall is the best time for cool-season grasses; late spring to early summer suits warm-season seed.
St. Augustine and other grasses that are not seeded
St. Augustine is planted as sod or plugs, so there is no seeding rate. Many zoysia lawns are also sodded; the zoysia rate above applies to seeded varieties only. Bermuda seed here means hulled seed; unhulled (common) bermuda seed needs about double.
Sources and how we chose the numbers
Cool-season ranges follow Purdue Extension AY-25-W (Kentucky bluegrass about 2 lb, turf-type tall fescue 6–9 lb, fine fescue mixes 4–5 lb per 1,000 sq ft), Virginia Cooperative Extension SPES-299-C, Table 1 (Kentucky bluegrass 2–3 lb, tall fescue 6–8 lb, fine fescue 3–5 lb, perennial ryegrass 3–5 lb, hulled bermuda 1–2 lb, zoysia 1–2 lb, centipede 0.25–0.5 lb) and University of Tennessee W160-B (tall fescue 5–8 lb, perennial ryegrass 4–6 lb, hulled bermuda 0.5–1 lb). Sources differ by a lot for warm-season grasses, so we show the range and default to a conservative middle value. Overseeding rates are our summary of extension guidance of roughly half to two-thirds of the new-lawn rate. Your local extension office and the seed label take priority.