Enter your lawn size and choose a new lawn or overseeding to get how many pounds of grass seed to buy.
Seed is measured by area. Multiply your lawn's length × width to get the square footage, divide by 1,000, then multiply by the seeding rate in pounds per 1,000 square feet. For example, a 2,000 sq ft lawn at 5 lb per 1,000 sq ft needs about 10 pounds of seed.
A new lawn needs a heavier rate — roughly 4 to 8 lb per 1,000 sq ft — because there's no existing grass. Overseeding an existing lawn to thicken it up uses about half that, around 2 to 4 lb per 1,000 sq ft. The calculator sets a sensible starting rate for each, but always adjust to your bag.
Tall fescue and ryegrass have larger seeds and are sown at the high end, while Kentucky bluegrass and Bermuda have tiny seeds and go on at much lower rates. Because of this, the most reliable number is the one printed on your seed bag — enter that for the best result.
This is a planning aid. Seeding rates vary a lot by grass type and are printed on your seed bag. Typical rates per 1,000 sq ft: a new lawn about 4–8 lb, overseeding about 2–4 lb. Tall fescue and ryegrass are on the high end; Kentucky bluegrass and Bermuda are much lower. Enter the rate from your bag for the best result.