Free landscaping calculator
Grass Seed Calculator — new lawn & overseeding
Pounds of seed for your lawn size and grass type — at new-lawn or overseeding rates.
Rates are for pure seed of each type. Seed blends list their own rate on the bag — when in doubt, follow the bag.
How much grass seed do I need?
Seeding rates are quoted in pounds per 1,000 square feet and vary widely by grass type — fine-bladed Bermuda needs only about 1.5 lb per 1,000 sq ft while tall fescue's larger seed takes 8 lb to cover the same area. Overseeding an existing lawn uses roughly half the new-lawn rate, since you're thickening turf rather than establishing it from bare soil.
| Grass type | New lawn | Overseeding |
|---|---|---|
| Bermuda | 1.5 | 0.75 |
| Kentucky bluegrass | 3 | 1.5 |
| Fine fescue | 5 | 2.5 |
| Tall fescue | 8 | 4 |
| Perennial ryegrass | 8 | 4 |
More seed is not better
Doubling the rate doesn't double the lawn — overcrowded seedlings compete for light and water, grow spindly, and invite fungal disease. Hitting the rate for your grass type, keeping the soil consistently moist for the first few weeks, and seeding at the right time of year matter far more than extra pounds of seed.
When to seed
Cool-season grasses (bluegrass, fescues, ryegrass) establish best in early fall, when soil is warm but the air has cooled — spring is the backup window. Warm-season grasses like Bermuda go down in late spring once soil temperatures stay above roughly 65°F. Seeding at the wrong end of the calendar is the most common reason new lawns fail.
Frequently asked questions
How much grass seed do I need for 1,000 square feet?
It depends on the grass: about 1.5 lb of Bermuda, 3 lb of Kentucky bluegrass, 5 lb of fine fescue, or 8 lb of tall fescue or perennial ryegrass for a new lawn. Overseeding uses about half those rates.
Can you put down too much grass seed?
Yes. Seeding far above the recommended rate crowds seedlings, which then compete for light, water, and nutrients, producing thin, weak grass that's prone to fungal disease. Stick close to the rate for your grass type.
When is the best time to plant grass seed?
Early fall for cool-season grasses like fescue, bluegrass, and ryegrass; late spring for warm-season grasses like Bermuda, once soil temperatures hold above about 65 degrees F.
Is seed or sod better for a new lawn?
Seed costs a fraction of sod and offers more grass varieties, but takes a season or two to fill in and needs diligent watering. Sod gives an instant, weed-resistant lawn at several times the price. Large areas usually favor seed; small, high-visibility areas favor sod.