Grass Seed Calculator
Calculate how much grass seed you need by grass type. Covers new lawns and overseeding with accurate coverage rates for every major grass variety.
How Much Grass Seed Do I Need?
The amount of grass seed you need depends on three factors: the size of your lawn, the type of grass you are planting, and whether you are seeding a new lawn or overseeding an existing one. Different grass types have dramatically different seeding rates. For example, Kentucky Bluegrass requires only 4 lbs per 1,000 square feet for a new lawn, while Tall Fescue requires 10 lbs per 1,000 square feet.
For new lawns, use the higher "new lawn" rate to ensure full coverage on bare soil. For overseeding an existing lawn, use the lower rate since you are filling in thin spots rather than starting from bare soil.
Grass Seed Coverage Rates
Coverage rates vary significantly by grass type:
| Grass Type | New Lawn (lbs/1,000 sq ft) | Overseeding (lbs/1,000 sq ft) |
|---|---|---|
| Bermuda | 2 | 1 |
| Centipede | 0.5 | 0.3 |
| Fine Fescue | 5 | 2.5 |
| Kentucky Bluegrass | 4 | 2 |
| Perennial Ryegrass | 10 | 5 |
| Tall Fescue | 10 | 5 |
| Bahia | 10 | 5 |
| Zoysia | 2 | 1 |
| Sun & Shade Mix | 6 | 3 |
Tips for Buying Grass Seed
- Check the label for the germination rate and weed seed percentage. Quality seed should have a germination rate above 85% and weed seed content below 0.5%.
- Buy from a local source when possible. Local suppliers stock varieties adapted to your regional climate.
- Match the grass to your conditions. If your yard has shade, choose a shade-tolerant variety like Fine Fescue. For full sun, Bermuda or Zoysia perform best.
- Store unused seed properly. Grass seed loses about 10-20% viability per year under normal storage conditions. Keep leftover seed in a cool, dry place in a sealed container. Use within one year for best results.
Why Does Seed Type Change How Much I Need?
Different grass species have dramatically different seed sizes. Kentucky Bluegrass seeds are tiny (about 2 million seeds per pound), so you only need 4 lbs to cover 1,000 sq ft. Tall Fescue seeds are much larger (about 230,000 seeds per pound), requiring 10 lbs for the same area. The calculator accounts for these differences automatically when you select your grass type.