Grass seed calculator: how much grass seed do I need?
6 to 8 lb
2,000 square feet at 3 to 4 lb per 1,000 sq ft (KBG + perennial rye) · for 50 × 40 ft
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Enter it the way you measured it: 4.5, 4 1/2,
3/8 or 10' 6".
6 to 8 lb
2,000 square feet at 3 to 4 lb per 1,000 sq ft (KBG + perennial rye)
Source: Purdue Extension AY-3-W, Establishing Turfgrass Areas, Table 2, recommended seeding rates for new lawns, in pounds per 1,000 square feet., read October 9, 2026. Data sheet (PDF)
A 50 by 40 ft lawn, 2,000 square feet, takes 6 to 8 lb of a Kentucky bluegrass and perennial rye mix to establish, at 3 to 4 pounds per 1,000 square feet. Pick your mix for its own rate.
A worked example
A 100 by 50 ft lawn sown with 100% tall fescue needs 30 to 45 lb. 5,000 square feet at 6 to 9 pounds per 1,000 square feet is 30 to 45 pounds.
How much grass seed per square foot?
For a new cool-season lawn the rate is given per 1,000 square feet, not per square foot, in Purdue Extension AY-3-W Table 2: 1.5 to 2.0 pounds for 100% Kentucky bluegrass, 3.0 to 4.0 for a bluegrass and perennial rye mix, 4.0 to 5.0 with fine fescue, and 6.0 to 9.0 for 100% tall fescue. Divide by 1,000 for a per-square-foot figure, so a bluegrass-rye mix is about 0.003 to 0.004 pounds, a little under a teaspoon, per square foot. Enter your lawn length and width above and pick the mix, and the page returns the pounds for the whole area. These are rates for sowing bare soil; overseeding a thin lawn uses about half.
What else it is called
Grass seed is sold by the pound and in bags marked with coverage. Cool-season mixes of Kentucky bluegrass, perennial rye and fescue are the ones these rates cover; warm-season grasses like Bermuda are sown lighter. The low end of each range is enough on good soil, the high end for a fast, thick stand.
Common sizes
| Lawn area | 100% Kentucky bluegrass | KBG + perennial rye | KBG + fine fescue | 100% tall fescue |
|---|---|---|---|---|
| 500 sq ft | 0.75–1 lb | 1.5–2 lb | 2–2.5 lb | 3–4.5 lb |
| 1,000 sq ft | 1.5–2 lb | 3–4 lb | 4–5 lb | 6–9 lb |
| 2,000 sq ft | 3–4 lb | 6–8 lb | 8–10 lb | 12–18 lb |
| 5,000 sq ft | 7.5–10 lb | 15–20 lb | 20–25 lb | 30–45 lb |
| 10,000 sq ft | 15–20 lb | 30–40 lb | 40–50 lb | 60–90 lb |
Pounds of seed for a new lawn: area ÷ 1,000 × the seeding rate. Rate range by mix from Purdue Extension AY-3-W, Table 2 (establishment rates).
Where the numbers come from
- Pounds of seed is the lawn area divided by 1,000, times the seeding rate for your mix. The rate is a range, so the result is a range too.
- Seeding rates: Purdue Extension AY-3-W, Establishing Turfgrass Areas, Table 2, recommended rates for new lawns in pounds per 1,000 square feet — 100% Kentucky bluegrass 1.5 to 2.0, bluegrass with perennial rye 3.0 to 4.0, bluegrass with fine fescue 4.0 to 5.0, and 100% tall fescue 6.0 to 9.0. Read October 9, 2026. Data sheet (PDF)
These are establishment rates for sowing a new lawn on bare soil. Overseeding an existing lawn uses about half as much, so halve the rate for that. The count is the lawn area you type in; it does not subtract beds, paths or the house.
By Javier Miralles · Last updated . How this site is made.
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