How much grass seed do I need?
Type the lawn area and pick the grass. The grass seed calculator gives the pounds of seed at the extension seeding rate (low and high ends), or at the rate on your seed label, and the bags to buy.
- Seed to buy
- 30 lb
Seeding 5,000 ft² needs about 30 lb of grass seed.
- At the low rate
- 30 lb
- At the high rate
- 30 lb
- Seeding rate used
- 6
Seed to buy: 30 lb. Seeding 5,000 ft² needs about 30 lb of grass seed.
How to calculate
Computes the pounds of grass seed for a new lawn from the area and the grass, using extension seeding rates per 1,000 sq ft, or a rate you type, with the bags to buy.
Example with the default inputs (Lawn area 5,000 ft², Grass Tall fescue, Rate unit lb per 1,000 sq ft): Seeding 5,000 ft² needs about 30 lb of grass seed.
Method: Seed = seeding rate (lb per 1,000 sq ft) × area ÷ 1,000 sq ft; with no rate typed, the high end of the grass’s rate; bags = seed ÷ bag weight, rounded up.
- Rates are NC State Extension’s for a new lawn (Table 9-4); mixes add the rate of each grass. The rate on your seed label comes first.
- For overseeding, type the rate from the seed label.
- 1 lb per 1,000 sq ft is about 4.88 g per m².
Worked examples
Each example is checked against the calculator on every build.
- Lawn area 5,000 ft², Grass Kentucky bluegrass, Rate unit lb per 1,000 sq ft gives Seed to buy 10 lb, At the low rate 7.5 lb, At the high rate 10 lb, Seeding rate used 2.Source: NC State Extension, Extension Gardener Handbook, chapter 9 Lawns, Table 9-4 Planting dates and rates for cool- and warm-season grasses (pounds of seed per 1,000 sq ft: Kentucky bluegrass 1.5–2; tall fescue 6; Kentucky bluegrass + fine fescue 1.5 + 1.5; Kentucky bluegrass + tall fescue 1 + 5; with fine fescue 1 + 5 + 1; Kentucky bluegrass + perennial ryegrass 1.5 + 1; bermudagrass 1–2; bahiagrass 5; centipedegrass 0.25–0.5; zoysiagrass 1–2), https://content.ces.ncsu.edu/extension-gardener-handbook/9-lawns (retrieved 2026-10-03)
- Lawn area 2,500 ft², Grass Tall fescue, Rate unit lb per 1,000 sq ft, Bag weight 5 lb gives Seed to buy 15 lb, Bags 3.Source: NC State Extension, Extension Gardener Handbook, chapter 9 Lawns, Table 9-4 Planting dates and rates for cool- and warm-season grasses (pounds of seed per 1,000 sq ft: Kentucky bluegrass 1.5–2; tall fescue 6; Kentucky bluegrass + fine fescue 1.5 + 1.5; Kentucky bluegrass + tall fescue 1 + 5; with fine fescue 1 + 5 + 1; Kentucky bluegrass + perennial ryegrass 1.5 + 1; bermudagrass 1–2; bahiagrass 5; centipedegrass 0.25–0.5; zoysiagrass 1–2), https://content.ces.ncsu.edu/extension-gardener-handbook/9-lawns (retrieved 2026-10-03)
- Lawn area 2,153 ft², Grass Tall fescue, My seeding rate 30, Rate unit g per m² gives Seed to buy 13.23 lb, Seeding rate used 6.144484.Source: NC State Extension, Extension Gardener Handbook, chapter 9 Lawns, Table 9-4 Planting dates and rates for cool- and warm-season grasses (pounds of seed per 1,000 sq ft: Kentucky bluegrass 1.5–2; tall fescue 6; Kentucky bluegrass + fine fescue 1.5 + 1.5; Kentucky bluegrass + tall fescue 1 + 5; with fine fescue 1 + 5 + 1; Kentucky bluegrass + perennial ryegrass 1.5 + 1; bermudagrass 1–2; bahiagrass 5; centipedegrass 0.25–0.5; zoysiagrass 1–2), https://content.ces.ncsu.edu/extension-gardener-handbook/9-lawns (retrieved 2026-10-03)
- Lawn area 3,000 ft², Grass Centipedegrass, Rate unit lb per 1,000 sq ft gives At the low rate 0.75 lb, At the high rate 1.5 lb.Source: NC State Extension, Extension Gardener Handbook, chapter 9 Lawns, Table 9-4 Planting dates and rates for cool- and warm-season grasses (pounds of seed per 1,000 sq ft: Kentucky bluegrass 1.5–2; tall fescue 6; Kentucky bluegrass + fine fescue 1.5 + 1.5; Kentucky bluegrass + tall fescue 1 + 5; with fine fescue 1 + 5 + 1; Kentucky bluegrass + perennial ryegrass 1.5 + 1; bermudagrass 1–2; bahiagrass 5; centipedegrass 0.25–0.5; zoysiagrass 1–2), https://content.ces.ncsu.edu/extension-gardener-handbook/9-lawns (retrieved 2026-10-03)
How it works
Seeding rates in pounds per 1,000 sq ft, from NC State Extension’s Table 9-4 (a mix adds the rate of each grass):
| Grass | Low | High |
|---|---|---|
| Tall fescue | 6 | 6 |
| Kentucky bluegrass | 1.5 | 2 |
| Kentucky bluegrass + fine fescue (1.5 + 1.5) | 3 | 3 |
| Kentucky bluegrass + tall fescue (1 + 5) | 6 | 6 |
| Kentucky bluegrass + tall fescue + fine fescue (1 + 5 + 1) | 7 | 7 |
| Kentucky bluegrass + perennial ryegrass (1.5 + 1) | 2.5 | 2.5 |
| Bermudagrass | 1 | 2 |
| Bahiagrass | 5 | 5 |
| Centipedegrass | 0.25 | 0.5 |
| Zoysiagrass (seeded) | 1 | 2 |
- At the low rate = low × area ÷ 1,000 sq ft; at the high rate = high × area ÷ 1,000 sq ft.
- Seed to buy = your rate × area when you type one; otherwise the high rate.
- Seeding rate used = your rate in lb per 1,000 sq ft (1 g per m² = 92.90304 ÷ 453.59237 lb per 1,000 sq ft, exactly; that is 1 ÷ 4.88242763…), or the high rate.
- Bags = seed to buy ÷ bag weight, rounded up; shown only when a bag weight is typed.
Rules. The area is above 0 and at most 10,000,000 m². Your rate is above 0 and at most 1,000. A bag weighs from 0.01 kg to 10,000 kg.
Exact arithmetic. Typed values are exact decimals (1 lb = 0.45359237 kg and 1 ft = 0.3048 m exactly). Results round once, for display.
Output format. Seed shows 2 decimals in pounds (kilograms in Metric); the rate shows 2 decimals; bags are whole numbers. The raw masses are in kilograms.
Worked examples by hand
5,000 sq ft of Kentucky bluegrass. 5 × 1.5 = 7.5 lb at the low rate; 5 × 2 = 10 lb at the high rate, the seed to buy.
2,500 sq ft of tall fescue, 5 lb bags. 2.5 × 6 = 15 lb; 15 ÷ 5 = 3 bags.
A label rate of 30 g per m² on 200 m². 200 × 30 g = 6 kg. In US terms that is 30 × 92.90304 ÷ 453.59237 = 6.14 lb per 1,000 sq ft.
3,000 sq ft of centipedegrass. 3 × 0.25 = 0.75 lb; 3 × 0.5 = 1.5 lb.
Other questions people ask
How much grass seed do I need per 1,000 sq ft?
It depends on the grass. NC State Extension gives 6 lb per 1,000 sq ft for tall fescue, 1.5 to 2 lb for Kentucky bluegrass, 1 to 2 lb for bermudagrass and zoysiagrass, 5 lb for bahiagrass and 0.25 to 0.5 lb for centipedegrass.
What if my grass is not in the list?
Pick any grass and type the rate from your seed label in “My seeding rate”. The calculator then uses your rate for the seed to buy and the bags.
How does the calculator handle a range such as 1.5 to 2 lb?
It shows the seed at both ends, and uses the high end as the seed to buy so you do not run short. Type your own rate to use that instead.
How do I seed a mix?
Pick the mix. NC State adds the rate of each grass: Kentucky bluegrass with tall fescue is 1 + 5 = 6 lb per 1,000 sq ft, and with fine fescue too, 1 + 5 + 1 = 7 lb.
Should I follow the bag label or the calculator?
The label. Seed blends differ in seed size and purity, and the maker’s rate allows for that. Type the label rate in “My seeding rate”; grams per square metre work too.
How much seed for overseeding?
Overseeding a thin lawn needs its own rate, which the seed label gives. Type it in “My seeding rate” for the pounds to buy.