Grass Seed Calculator
A new lawn needs about 1 pound of grass seed per 250 square feet; overseeding an existing lawn takes about half that.
Seeding rates depend on whether you are starting from bare soil or thickening an existing lawn. Pick the scenario below and the calculator converts your lawn area into pounds of seed.
Grass seed calculator
You need
0lb
- Area covered
- 0 sq ft
- Including waste
- 0 sq ft
- Estimated cost
- $0
Rates reflect typical cool-season blends (tall fescue, perennial ryegrass). Always check the seed label. Estimates only — confirm with your supplier before ordering.
Grass seed coverage by option
| Option | Covers | Per 500 sq ft |
|---|---|---|
| New lawn (1 lb per 250 sq ft) | 250 sq ft | 2 lb |
| Overseeding (1 lb per 500 sq ft) | 500 sq ft | 1 lb |
Grass seed questions people actually ask
- How much grass seed do I need per 1,000 square feet?
- About 4 pounds for a new lawn and 2 pounds for overseeding, using a typical tall fescue or ryegrass blend. Fine fescues and bluegrass have smaller seeds and use lower rates.
- Can I use too much grass seed?
- Yes. Over-seeding crowds seedlings, and they compete for water and light instead of establishing deep roots. Stay within 25 percent of the label rate.
- When should I seed?
- Early fall is best for cool-season grasses; late spring for warm-season types. Soil temperature matters more than air temperature.
Gear for a grass seed job
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Related calculators
- Sod CalculatorA standard pallet of sod covers about 450 square feet, and a single roll covers about 10 square feet.
- Topsoil CalculatorOne cubic yard of screened topsoil covers about 108 square feet at 3 inches deep and weighs roughly 1.1 tons.
- Compost CalculatorOne cubic yard of compost topdresses about 650 square feet of lawn at a quarter inch, or fills 108 square feet of bed at 3 inches deep.
- Mulch CalculatorA cubic yard of mulch covers about 108 square feet at 3 inches deep, so most beds need roughly 1 cubic yard (13.5 two-cubic-foot bags) per 100 square feet.
How this number is calculated
Rates reflect typical cool-season blends (tall fescue, perennial ryegrass). Always check the seed label. Counts are the total area divided by the coverage of one unit, rounded up, with your waste allowance applied. See all our assumptions.