Grass Seed Calculator – How Much Do I Need? | CalcLoft
Find out exactly how much grass seed you need — for a brand new lawn or overseeding an existing one — in pounds and 5-lb bags.
How to calculate grass seed for a lawn
Grass seed is sold by weight, so the math is simple: figure out your lawn area in square feet, divide by 1,000, and multiply by the seeding rate in pounds per 1,000 sq ft:
Seed needed (lb) = lawn area (sq ft) ÷ 1,000 × rate (lb per 1,000 sq ft)
For example, a 2,000 sq ft lawn at the standard new-lawn rate of 6 lb per 1,000 sq ft needs 2000 ÷ 1000 × 6 = 12 lb of grass seed — three 5-lb bags.
Grass seed needed by lawn size — new lawn
New lawns are seeded on bare, prepared soil. At a typical rate of 6 lb per 1,000 sq ft, here is what you need by lawn size:
| Lawn size (sq ft) | Seed needed |
|---|---|
| 500 | 3 lb |
| 1,000 | 6 lb |
| 2,000 | 12 lb |
| 5,000 | 30 lb |
| 10,000 | 60 lb |
Grass seed needed by lawn size — overseeding
Overseeding thickens a thin or patchy existing lawn, so it needs about half the seed. At a typical overseeding rate of 3 lb per 1,000 sq ft:
| Lawn size (sq ft) | Seed needed |
|---|---|
| 1,000 | 3 lb |
| 2,000 | 6 lb |
| 5,000 | 15 lb |
| 10,000 | 30 lb |
Rates vary by grass variety, seed size and quality — these tables are typical figures. Always follow the seeding rate printed on your seed bag.
Related guides
Grass seed calculator FAQ
How much grass seed do I need per 1,000 sq ft?
For a new lawn, plan on about 6 lb per 1,000 sq ft — most varieties fall in the 5–10 lb range depending on seed size and quality. When overseeding an existing lawn, use about half that: 2–4 lb per 1,000 sq ft.
What is the difference between new lawn seeding and overseeding?
A new lawn is seeded on bare, prepared soil, so it needs more seed — usually 6–10 lb per 1,000 sq ft — to fill in evenly. Overseeding drops seed into existing grass to thicken a thin or patchy lawn, and since the existing turf shades and competes with new seedlings, a lighter rate of 2–4 lb per 1,000 sq ft is enough.
How much area does a 5-lb bag of grass seed cover?
At the standard new-lawn rate of 6 lb per 1,000 sq ft, a 5-lb bag covers roughly 830 sq ft. At the lighter overseeding rate of 3 lb per 1,000 sq ft, the same bag stretches to about 1,670 sq ft.
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