Grass Seed Calculator
Pick your grass type, enter the lawn area and choose a new lawn or overseeding. You'll get the pounds of seed to buy from university extension seeding rates.
- Tested formulas
- Feet or metric
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2 What to buy
Updates as you type| Grass | Tall fescue |
|---|---|
| Type | Cool-season |
| Job | Seeding a new lawn |
| Seed at the low rate | 25 lb |
| Seed at the high rate | 40 lb |
Cool-season grasses do best sown in late summer to early fall, roughly mid-August to early October in much of the country. Spring seeding is a second choice.
Buy for the high end of the range if the seed bag doesn't list a rate. If it does, the bag's rate wins: coated seed and blends with lots of filler cover less ground per pound.
Quick answer
Pounds of seed = seeding rate × area ÷ 1,000. Tall fescue goes down at 5–8 lb per 1,000 sq ft for a new lawn, so 5,000 sq ft needs 25 to 40 lb. Kentucky bluegrass needs only 1 to 3 lb per 1,000 sq ft.
Grass seeding rates by type
| Grass | Season | New lawn | Overseeding |
|---|---|---|---|
| Tall fescue | Cool | 5–8 lb | 2–6 lb |
| Kentucky bluegrass | Cool | 1–3 lb | 1–2 lb |
| Perennial ryegrass | Cool | 4–6 lb | 4–6 lb |
| Fine fescue | Cool | 4–5 lb | 2–4 lb |
| Bermudagrass (hulled seed) | Warm | 1–2 lb | n/a |
| Bermudagrass (unhulled seed) | Warm | 3–6 lb | n/a |
| Zoysiagrass | Warm | 1–3 lb | n/a |
| Centipedegrass | Warm | 0.25–1 lb | n/a |
| Bahiagrass | Warm | 3–8 lb | n/a |
| Buffalograss (burs) | Warm | 1–2 lb | n/a |
Pounds per 1,000 sq ft. Sources: Georgia, Tennessee, Kentucky, Nebraska and Suffolk County (Cornell) extension. We found no extension overseeding rate for warm-season grasses. Use the calculator above for your exact size.
How much grass seed per square foot
Seeding rates are given in pounds per 1,000 square feet. Multiply the rate by your area in thousands of square feet. Small-seeded grasses like Kentucky bluegrass need very little per square foot, while big-seeded tall fescue and ryegrass need several times more by weight.
Worked example: a new 5,000 sq ft tall fescue lawn
- Tall fescue goes down at 5–8 lb per 1,000 sq ft for a new lawn (University of Tennessee).
- 5,000 sq ft is 5 × 1,000, so you need 25 to 40 lb of seed.
- To overseed the same lawn when it's thin, Georgia Extension suggests 2 to 6 lb per 1,000 sq ft, about 10 to 30 lb.
When to sow
- Cool-season grasses (fescues, bluegrass, ryegrass): late summer into early fall. Missouri Extension gives August 25 to October 10, and Kentucky mid-August to late September. Spring seeding works, but the young grass has to face summer heat right away.
- Warm-season grasses (bermuda, zoysia, centipede, bahia, buffalograss): late spring to early summer, once the soil is about 65°F at 4 inches deep, per Georgia Extension.
Getting seed to come up
- Loosen the top inch or two of soil and rake it level. Seed sitting on hard ground or thatch mostly feeds birds.
- Many gardeners spread half the seed in one direction and half crosswise for even coverage, then rake it in lightly.
- Keep the surface damp, not soaked, until the grass is up. In warm, dry weather that often means light watering once or twice a day.
- Check the bag label. Coated seed and cheap mixes with filler cover less ground per pound, and the label's rate beats any chart.
Frequently asked questions
How much grass seed do I need per 1,000 square feet?
It depends on the grass: about 5 to 8 lb for tall fescue, 4 to 6 lb for perennial ryegrass, 1 to 3 lb for Kentucky bluegrass, 1 to 2 lb for hulled bermudagrass and as little as ¼ to 1 lb for centipedegrass.
How much seed do I need to overseed?
Usually the same or less than for a new lawn. Suffolk County's Cornell extension gives 4 to 6 lb of ryegrass, 2 to 4 lb of fine fescue and 1 to 2 lb of Kentucky bluegrass per 1,000 sq ft. Georgia Extension uses 2 to 6 lb of tall fescue on thin areas. In the South, overseeding often means sowing ryegrass into a dormant warm-season lawn for winter color; Georgia gives 5 to 10 lb per 1,000 sq ft for that.
Can I put down too much grass seed?
Yes. Seedlings that come up too thick crowd each other for water and light, so more seed doesn't mean a thicker lawn. Stick to the rate on the bag or the chart above.
When is the best time to plant grass seed?
Early fall for cool-season grasses like fescue and bluegrass; late spring to early summer for warm-season grasses like bermuda and zoysia, once the soil has warmed.
How much will a 50 lb bag of grass seed cover?
For a new tall fescue lawn at 5 to 8 lb per 1,000 sq ft, a 50 lb bag covers about 6,250 to 10,000 sq ft. Small-seeded grasses like Kentucky bluegrass go much further; the bag label lists its own rate.
Last reviewed 2026-10-23. See how we calculate for our sources and assumptions.