Grass Seed Calculator
Find how much grass seed your lawn needs. Enter the area and a seeding rate — use a higher rate for a new lawn and a lower one for overseeding.
Example: with Lawn length 50 ft · Lawn width 30 ft · Seeding rate 5 lbs/1000 sq ft → Seed needed: 7.5 lbs.
- Lawn area1,500 sq ft
Computed by the calculator below using its default values. Change any input to see your own numbers.
3D lawn · drag to rotate
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Check it outSeeding rates
New lawns typically need about 5–8 lbs of seed per 1,000 square feet, while overseeding an existing lawn uses roughly half that. Rates vary by grass type — check the bag, since fine fescues and ryegrasses differ. Even coverage and good soil contact matter more than dumping on extra seed.
How it’s calculated
This calculator returns its result directly from the values you enter using standard arithmetic for this calculation; all figures are estimates for general information.
Results update as you type and are estimates, not professional advice — verify important decisions with a qualified professional.
Common mistakes
- Using the new-lawn rate when overseeding (about half is enough).
- Over-seeding, which crowds and weakens seedlings.
Frequently asked questions
New lawn vs. overseeding?
New lawns use a higher rate (around 5–8 lbs per 1,000 sq ft); overseeding uses about half.
Does grass type matter?
Yes — seed size and recommended rates differ by species. Follow the bag's guidance for best results.
Can I use too much seed?
Yes. Overcrowded seedlings compete and grow weaker. Aim for even coverage at the recommended rate.