Grass Seed Calculator
This grass seed calculator tells you how many pounds of seed to buy for your lawn. Enter the area, pick the grass type and choose whether you are seeding bare soil or overseeding an existing lawn. It multiplies your area by a typical seeding rate per 1,000 square feet and shows the result in pounds and kilograms.
The built-in rates are mid-range values from the ranges commonly published by university extension services and seed suppliers. Seed blends, coated seed and specific varieties can call for different amounts, so if your bag lists a rate, type it in and the calculator will use that instead. The rate on the label always wins.
Grass Seed Calculator
How to Use the Grass Seed Calculator
- 1
Choose units and enter the area
Select US or Metric, then enter the length and width of the lawn or switch to Total area and type the square footage.
- 2
Pick the grass type
Choose from Kentucky bluegrass, tall fescue, perennial ryegrass, fine fescue, Bermudagrass, zoysiagrass, centipedegrass or buffalograss.
- 3
Choose new lawn or overseeding
New lawn uses the higher rate for bare soil. Overseeding uses a lower rate to thicken existing turf.
- 4
Add your bag rate if you have it
Type the rate printed on the seed bag to override the typical rate, then read the pounds of seed and the published range for your area.
How the grass seed calculator works
Seeding rates are quoted in pounds of seed per 1,000 square feet. The calculator finds your lawn area in square feet, converting from square meters if needed, then multiplies it by the rate for your grass and job and divides by 1,000.
In metric mode the rate is shown in grams per square meter. One pound per 1,000 sq ft equals about 4.88 g per square meter. Below the result you also see the pounds needed at the low and high ends of the published range, so you can see how much the answer could reasonably vary.
Seed (lb) = rate (lb per 1,000 sq ft) × area (sq ft) ÷ 1,000
Seed (kg) = seed (lb) × 0.4536
1 lb per 1,000 sq ft ≈ 4.88 g per m²Worked example: a new tall fescue lawn
Overseeding the same 2,000 sq ft with Kentucky bluegrass at 1.5 lb per 1,000 sq ft takes only 3 lb of seed. Bluegrass seed is tiny, with far more seeds per pound than fescue, which is why its rate is so much lower.
- Lawn: 50 × 40 ft = 2,000 sq ft of bare soil.
- Typical new-lawn rate for tall fescue: 7 lb per 1,000 sq ft (published range 6 to 8).
- Seed needed: 7 × 2,000 ÷ 1,000 = 14 lb, or 6.35 kg.
- Published range for this area: 12 to 16 lb.
Typical seeding rates by grass type
Pounds of seed per 1,000 sq ft. The value in brackets is the one the calculator uses. Always check the rate on your seed bag first.
| Grass | New lawn | Overseeding | Seed for 5,000 sq ft (new / overseed) |
|---|---|---|---|
| Kentucky bluegrass | 2 to 3 (2.5) | 1 to 2 (1.5) | 12.5 lb / 7.5 lb |
| Tall fescue | 6 to 8 (7) | 3 to 5 (4) | 35 lb / 20 lb |
| Perennial ryegrass | 6 to 8 (7) | 3 to 5 (4) | 35 lb / 20 lb |
| Fine fescue | 4 to 5 (4.5) | 2 to 3 (2.5) | 22.5 lb / 12.5 lb |
| Bermudagrass (hulled) | 1 to 2 (1.5) | 0.5 to 1 (0.75) | 7.5 lb / 3.75 lb |
| Zoysiagrass | 1 to 2 (1.5) | 0.5 to 1 (0.75) | 7.5 lb / 3.75 lb |
| Centipedegrass | 0.25 to 0.5 (0.4) | 0.25 (0.25) | 2 lb / 1.25 lb |
| Buffalograss | 2 to 3 (2.5) | 1 to 2 (1.5) | 12.5 lb / 7.5 lb |
Tips for better results
- Match the grass to your climate. Cool-season grasses such as bluegrass, fescue and ryegrass suit northern and transition areas; Bermuda, zoysia, centipede and buffalograss suit warm regions.
- Seed at the right time. Late summer to early fall is usually best for cool-season grasses, and late spring to early summer for warm-season grasses.
- More seed is not better. Sowing far above the recommended rate makes seedlings compete for light and water, and can leave a weaker lawn.
- Good seed-to-soil contact matters more than extra seed. Rake lightly after spreading, and keep the surface consistently moist until the seedlings are established.
- Winter overseeding of dormant Bermuda with ryegrass for green winter color uses much heavier rates than normal overseeding. Follow the seed label for that job.
Why the bag label takes priority
Seeding rates are ranges, not exact numbers. Seed size differs between varieties, coated seed weighs more per seed, and mixes combine grasses with very different rates. The seed bag lists a rate for that exact product, often with separate figures for new lawns and overseeding.
Enter the label rate in the optional field and the calculator uses it instead of the typical value. If you are unsure which grass suits your site, a local extension office or garden center can advise on varieties that do well in your area.
Features
- Eight common grass types, cool-season and warm-season
- New lawn and overseeding rates
- Override with the rate printed on your seed bag
- Pounds and kilograms, with a published low-to-high range
- Area by length × width or total area, in feet or meters
- Seeding rate reference table
Frequently Asked Questions
How much grass seed do I need per 1,000 square feet?
It depends on the grass. Typical new-lawn rates per 1,000 sq ft are about 2 to 3 lb for Kentucky bluegrass, 6 to 8 lb for tall fescue and perennial ryegrass, 4 to 5 lb for fine fescue and 1 to 2 lb for hulled Bermuda or zoysia. Overseeding uses roughly half. The rate on your seed bag is the one to follow.
How much grass seed do I need for 5,000 square feet?
For a new tall fescue lawn at 7 lb per 1,000 sq ft, 5,000 sq ft needs 35 lb of seed. Overseeding the same area at 4 lb per 1,000 sq ft takes 20 lb. For Kentucky bluegrass the figures are 12.5 lb for a new lawn and 7.5 lb for overseeding, using the mid-range rates in this calculator.
How much seed do I need to overseed a lawn?
Overseeding rates are usually about half of new-lawn rates, because existing grass already covers part of the ground. Typical overseeding rates are 1 to 2 lb per 1,000 sq ft for Kentucky bluegrass and 3 to 5 lb for tall fescue or perennial ryegrass. Choose Overseeding in the calculator and check the label on your seed.
Can I put down too much grass seed?
Yes. Heavy seeding creates crowded seedlings that compete for light, water and nutrients, and thin, weak grass can be more prone to disease. It also wastes money. Stick close to the label rate, prepare the soil well and keep it moist, which does far more for a thick lawn than extra seed.
How many kilograms of grass seed do I need per square meter?
Rates in metric are usually given in grams per square meter. One pound per 1,000 sq ft is about 4.88 g per m², so a tall fescue rate of 7 lb per 1,000 sq ft is about 34.2 g per m². For a 200 m² new tall fescue lawn, that works out to about 6.84 kg of seed.
Why is the rate for Bermuda or centipede so low?
Warm-season grasses such as hulled Bermudagrass and centipedegrass have very small seeds, so each pound contains far more seeds than a pound of tall fescue or ryegrass. That is why a new Bermuda lawn needs only about 1 to 2 lb per 1,000 sq ft and centipede only about 0.25 to 0.5 lb, compared with 6 to 8 lb for tall fescue.
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