How to use the grass seed calculator
Choose your grass and enter the lawn's size. For a new lawn the calculator uses the full seeding rate. For overseeding, estimate how much of the lawn is thin or bare; following the University of Georgia's method, it scales the full rate by that share. If your seed bag gives its own rate, choose "Rate from my seed bag" and enter it.
The formula
pounds = area ÷ 1,000 × rate (lb per 1,000 ft²)
overseeding rate = full rate × share of lawn that's thin
bags = pounds ÷ bag size, rounded up
Worked example: a new 50 × 40 ft tall fescue lawn
- Area: 2,000 ft².
- Rate: UGA recommends 5-6 lb per 1,000 ft²; the calculator uses 5.5.
- Seed: 2 × 5.5 = 11 lb, so one 20 lb bag (or two 7 lb bags).
Overseeding the same lawn where about half the grass is gone: 5.5 × 0.5 = 2.75 lb per 1,000 ft², 5.5 lb in all.
Seeding rates (new lawns)
| Grass | lb per 1,000 ft² | Season |
|---|---|---|
| Tall fescue | 5-6 | Cool |
| Fine fescues | 4-5 | Cool |
| Kentucky bluegrass | 1-3 | Cool |
| Annual and perennial ryegrass | 5-10 | Cool; used for overseeding |
| Bahiagrass | 3-8 | Warm |
| Bermudagrass (hulled) | 1-2 | Warm |
| Zoysiagrass | 1-3 | Warm |
| Centipedegrass | ¼-1 | Warm |
From University of Georgia Extension Bulletin 1533. Rates elsewhere are similar; your local extension service can recommend varieties for your area.
Getting seed to grow
- Seed-to-soil contact is everything. Rake or slit-seed so seed sits in loose soil, not on top of thatch.
- Split the seed into two halves and spread them in perpendicular directions for even coverage.
- Keep it moist, not soaked: light watering once or twice a day until it's established.
- Cover lightly with straw: UGA notes one 60-80 lb bale of wheat straw covers about 1,000 ft².
- No pre-emergent weed killer before seeding; it stops grass seed too.
Questions people ask
How much grass seed do I need per 1,000 square feet?
It depends on the grass. University of Georgia Extension recommends 5 to 6 lb of tall fescue, 4 to 5 lb of fine fescue, 1 to 3 lb of Kentucky bluegrass, 1 to 2 lb of hulled bermudagrass, 1 to 3 lb of zoysia and ¼ to 1 lb of centipede per 1,000 square feet for a new lawn.
How much seed do I need to overseed?
Less than for a new lawn. UGA's method for tall fescue is to estimate the share of the lawn that's thin or bare and multiply by the full rate: if half the stand is lost, use 0.5 × 6 = 3 lb per 1,000 square feet. For general thin spots, UGA suggests 2 to 6 lb.
How much grass seed for an acre?
Multiply the rate per 1,000 square feet by 43.56. Tall fescue at 6 lb per 1,000 is about 260 lb per acre.
Is it better to put down too much grass seed?
No. Seeding far above the recommended rate makes seedlings compete for light, water and nutrients, and the stand can thin out and get diseased. Stick to the rate on the bag or from your extension service.
When is the best time to plant grass seed?
Cool-season grasses (fescues, bluegrass, ryegrass) do best seeded in early fall, with late winter to early spring second. Warm-season grasses (bermuda, zoysia, centipede) are seeded in late spring to early summer once soil is warm.
Sources and assumptions
- University of Georgia Extension, Bulletin 1533: Lawns in Georgia: Establishment (seeding rates, overseeding method)
- Default rates are the middle of UGA's ranges. Seed bags list their own rates, which can differ for coated seed or blends; use the bag's rate if it's given.
Last reviewed 27 October 2026. Every formula on this page is checked against the worked example above in our automated tests. Found a problem? Tell us.