Keep the top inch moist with light watering once or twice a day until the grass is about two inches tall.
How the grass seed calculator works
GrassSeedCalc multiplies your lawn area in thousands of square feet by the seeding rate for the grass you choose. The rates are midpoints of the ranges published by US university extension services, in pounds of pure, uncoated seed per 1,000 square feet: the full rate for a new lawn on bare soil, and about half for overseeding an existing lawn. Coated seed can be up to half coating by weight, so the coated option doubles the rate. Bags are rounded up to whole bags, and the per-acre figure is the rate × 43.56, since an acre is 43,560 square feet. Areas in acres or square metres are converted to square feet first.
Seeding rates by grass type
| Grass | New lawn (lb/1,000 sq ft) | Overseed (lb/1,000 sq ft) | New lawn (lb/acre) | Type |
|---|---|---|---|---|
| Tall fescue | 8 | 4 | 348 | cool-season |
| Kentucky bluegrass | 2.5 | 1.5 | 109 | cool-season |
| Perennial ryegrass | 7 | 4 | 305 | cool-season |
| Fine fescue | 4.5 | 2.5 | 196 | cool-season |
| Sun & shade mix | 5 | 2.5 | 218 | cool-season |
| Bermudagrass (hulled) | 1.5 | 1 | 65 | warm-season |
| Zoysiagrass | 1.5 | 1 | 65 | warm-season |
| Centipedegrass | 0.5 | 0.25 | 22 | warm-season |
| Bahiagrass | 8 | 5 | 348 | warm-season |
| Buffalograss | 2.5 | 1.5 | 109 | warm-season |
Follow the rate on your seed bag when it differs: blends, mixes and seed quality vary. Germination needs good seed-to-soil contact and steady moisture. Results are estimates.
Frequently asked questions
How much seed for a 1,000 sq ft new lawn?
About 8 lb of tall fescue, 7 lb of perennial ryegrass or 2.5 lb of Kentucky bluegrass.
Should I cover grass seed with topsoil?
Only lightly: rake it in to about 1/4 inch or cover with a thin layer of straw or peat moss.
When can I mow new grass?
When it reaches about 3–4 inches, cutting off no more than a third of the height.
Is GrassSeedCalc free?
Yes, with no sign-up or ads.
Are my numbers saved?
Yes, in this browser only.