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Grass Seed Calculator

Calculate how much grass seed to buy for new lawns or overseeding. Seven seed types with recommended rates, bag count, and cost.

Lawn area, grass type, and seeding

Seed needed

18 lb

Range: 16 to 20 lb (7.26 to 9.07 kg)

Lawn area
2,000 sq ft (185.8 sq m)
Rate
8 to 10 lb / 1,000 sq ft
Coverage at low rate
125 sq ft per lb
Coverage at high rate
100 sq ft per lb
Germination
7-12 days
Season
Cool-season grass

Early fall (late August through mid-October) is the best window for cool-season grasses. Spring (March through May) is the second-best option but expect more weed pressure.

St. Augustine is not seeded. It is established from sod, plugs, or sprigs only.

Frequently Asked Questions about the Grass Seed Calculator

How much grass seed do I need?
Seeding rate depends on grass type and whether you are starting new or overseeding. Kentucky bluegrass: 2-3 lb per 1,000 sq ft new (1-2 overseed). Tall fescue: 6-8 (3-4). Perennial rye: 5-9 (4-6). Bermuda (hulled): 1-2 (0.5-1). The calculator covers seven common types.
When should I seed my lawn?
Cool-season grasses (fescue, ryegrass, bluegrass): late summer through early fall is best (warm soil, cool air, less weed competition). Warm-season (Bermuda, Zoysia, Bahia): late spring through early summer when soil is 65 F+.
What is the difference between new lawn and overseeding rates?
New lawns need full coverage from seed alone, so rates are roughly double overseeding rates. Overseeding adds seed to an existing lawn to thicken it; the existing turf does most of the work, so less seed is needed per area.
How long does grass seed take to germinate?
Ryegrass: 5-10 days. Bermuda: 7-21 days. Tall fescue: 7-14 days. Kentucky bluegrass: 14-30 days (slow). Keep the seedbed consistently moist (not soaked) for the full germination window. Water lightly twice a day until established.
Should I use a starter fertilizer?
Yes. A starter (high phosphorus, like 18-24-12) gives seedlings the root nutrients they need. Apply at seeding, water in, and skip a second feeding until the new lawn has been mowed 2-3 times.