Grass seed calculator.
Sow too little seed and weeds fill the gaps; sow too much and the seedlings choke each other. Enter your lawn size and grass type for a sensible amount - for a brand new lawn or for overseeding a tired one.
Lawn area:
Sowing rate:
Tip: buy about 10% extra for edges, patching and birds, and always check the rate printed on your seed bag - it beats any calculator, since it's matched to that exact blend. Cool-season new-lawn rates follow Penn State Extension's seeding table (Kentucky bluegrass 2-3 lb, fine fescues and perennial ryegrass 4-5 lb, turf-type tall fescue 6-8 lb per 1,000 sq ft); the calculator uses the middle of each range. Bermuda follows the University of Kentucky's Seeded Bermudagrass note (about 1 lb per 1,000 sq ft; double that for coated seed). Overseeding at half the new-lawn rate is our rule of thumb, not a figure from these tables: a very thin lawn may need more.
Sowing rates are typical ranges and vary by cultivar and supplier - the figure on your seed bag is the authority. Sow into well-prepared, raked soil, keep it lightly moist until germination, and sow in the right season for your grass (early autumn for cool-season, late spring for warm-season).