Grass seed calculator
Measure the lawn, choose a grass type, and see how many pounds of seed to buy for a new lawn or for overseeding thin turf.
Estimates round up. Check product labels and supplier figures before ordering.
Grass seeding rates
| Grass type | New lawn (lb per 1,000 sq ft) | Overseeding |
|---|---|---|
| Tall fescue | 6-8 | 3-4 |
| Kentucky bluegrass | 2-3 | 1-1.5 |
| Perennial ryegrass | 7-8 | 3.5-4 |
| Fine fescue | 3-6 | 1.5-3 |
| Bermudagrass (hulled) | 0.5-1 | 0.25-0.5 |
| Zoysiagrass | 1-2 | 0.5-1 |
How it's calculated
Seed is sold by weight, and every grass has its own seeding rate in pounds per 1,000 square feet. The calculator scales that rate to your lawn and halves it for overseeding, a common extension rule of thumb.
Pounds of seed = area (sq ft) / 1,000 x rate (lb per 1,000 sq ft) x job factor
Job factor = 1 for a new lawn, 0.5 for overseeding
Example: a 5,000 sq ft new tall fescue lawn at 7 lb per 1,000 sq ft needs 35 lb of seed, which is two 20 lb bags. Overseeding the same lawn takes about 17.5 lb.
The default rates sit in the middle of ranges published by university turf programs such as Ohio State, Kansas State and Tennessee. Small-seeded grasses like bluegrass and bermudagrass need far fewer pounds because each pound holds millions of seeds. Coated seed weighs more, so the bag rate can be up to double. Use the bag's own rate when it differs.
What you'll need
- Grass seed
- Broadcast spreader
- Starter fertilizer
- Seed starting mulch
- Lawn aerator rental
Common questions
How much grass seed do I need per 1,000 square feet?
It depends on the grass. Tall fescue needs about 6 to 8 lb for a new lawn, Kentucky bluegrass 2 to 3 lb, and hulled bermudagrass about 1 lb.
How much seed do I need to overseed?
About half the new-lawn rate. For tall fescue that is roughly 3 to 4 lb per 1,000 square feet.
Can I put down too much grass seed?
Yes. Seeding far above the recommended rate crowds seedlings, which then compete for water and light and are more prone to disease.
When is the best time to plant grass seed?
Late summer to early fall for cool-season grasses such as fescue and bluegrass. Late spring to early summer, once soil is warm, for bermudagrass and zoysia.