Pasture and erosion-control seedings often use different mixes and rates, so check with your local extension office for those.
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 many pounds of grass seed per acre?
For lawns: about 350 lb of tall fescue, 110 lb of Kentucky bluegrass, 300 lb of perennial ryegrass or 65 lb of hulled Bermuda for a new seeding.
How many square feet are in an acre?
43,560 square feet.
How much does it cost to seed an acre?
Seed alone is often a few hundred dollars per acre for lawn grasses, plus soil preparation and equipment.
Is GrassSeedCalc free?
Yes, with no sign-up or ads.
Are my numbers saved?
Yes, in this browser only.