Grass Seed Coverage Calculator
Buying too little seed means patchy coverage; buying too much wastes money and risks over-seeding, which creates excessive competition among seedlings. This calculator multiplies your lawn area by the seeding rate appropriate for your grass type and whether you are starting fresh or overseeding. Seeding rates referenced here follow USDA Cooperative Extension recommendations for common turf grass species in the continental United States. Enter your lawn area in square feet and choose a seeding rate to get the total pounds of seed needed.
Grass seed coverage formula
Seed (lb) = Lawn area (sq ft) x Seeding rate (lb / 1,000 sq ft) / 1,000
To convert pounds to kilograms, divide by 2.205. Typical new seeding rates: tall fescue 6 to 8 lb/1,000; Kentucky bluegrass 2 to 3 lb/1,000; perennial ryegrass 6 to 9 lb/1,000; Bermudagrass 1 to 2 lb/1,000.
Grass seed rate quick reference
- Tall fescue (new lawn): 6 to 8 lb per 1,000 sq ft.
- Tall fescue (overseeding): 3 to 4 lb per 1,000 sq ft.
- Kentucky bluegrass (new): 2 to 3 lb per 1,000 sq ft.
- Perennial ryegrass (new): 6 to 9 lb per 1,000 sq ft.
- Bermudagrass, hulled (new): 1 to 2 lb per 1,000 sq ft.
- Centipede grass (new): 0.25 to 0.5 lb per 1,000 sq ft.
Grass seed coverage calculator: frequently asked questions
How much grass seed do I need per 1,000 sq ft?
It depends on the grass species. Tall fescue: 6 to 8 lb per 1,000 sq ft for new seeding, 3 to 4 lb for overseeding. Kentucky bluegrass: 2 to 3 lb for new seeding. Bermudagrass (hulled): 1 to 2 lb. Consult the seed bag label and your local Cooperative Extension for region-specific rates.
What is the difference between new seeding and overseeding rates?
New seeding fills bare ground and uses full rates (often 6 to 8 lb/1,000 sq ft for fescue). Overseeding thickens an existing lawn and typically uses 50 percent of the new seeding rate since the existing turf covers some soil.
How do I measure my lawn area?
For rectangular lawns, multiply length by width in feet. For irregular shapes, divide into rectangles or triangles and sum the areas. USDA extension guides also recommend using a measuring wheel or online satellite map tool for odd-shaped properties.
When is the best time to seed?
Cool-season grasses (fescue, bluegrass, ryegrass) establish best in late summer to early fall (August through October in most of the US) when soil temperatures are 50 to 65 degrees Fahrenheit. Warm-season grasses (Bermuda, Zoysia) germinate best in late spring when soil temperatures exceed 65 degrees Fahrenheit.
Does germination rate affect how much seed I need?
Seed labels report a germination percentage. If germination is 85 percent, you may want to increase your application rate by 15 to 20 percent to compensate for seeds that do not sprout. High-quality seed typically exceeds 85 percent germination.
Official sources
- USDA NRCS Plant Materials Program: nrcs.usda.gov.
- USDA National Institute of Food and Agriculture, Cooperative Extension: nifa.usda.gov.
Reviewed by the CalculatorHub team, edited by James Graham, 15 June 2026. See our methodology.