Grass Seed Calculator
How many pounds of grass seed does your lawn need?
How this is calculated
- Lawn area = length × width
- Pounds of seed = (lawn area ÷ 1000) × seeding rate (lb per 1000 sq ft)
- Seeding rate depends on grass type: Kentucky bluegrass 2–3, perennial rye 5–7, tall fescue 8–10 lb per 1000 sq ft for a new lawn; halve it when overseeding.
Common questions
How much grass seed do I need for a 5000 sq ft lawn?
For a new lawn at a typical 5 lb per 1000 sq ft rate (perennial ryegrass region), you need 25 lb of seed. Overseeding the same lawn needs roughly half — about 12–13 lb.
What seeding rate should I use?
New lawns: Kentucky bluegrass 2–3 lb/1000 sq ft, perennial ryegrass 5–7, tall fescue 8–10. For overseeding an existing lawn, use about half the new-lawn rate. More is not better — overcrowded seedlings compete and die off.
When is the best time to plant grass seed?
Cool-season grasses (fescue, bluegrass, rye): late summer to early fall — soil is warm, air is cooling, weeds are fading. Second-best is early spring. Warm-season grasses (Bermuda, zoysia, St. Augustine): late spring to early summer once soil reaches 65–70°F.
Can I just spread more seed for a thicker lawn?
No — overseeding at 2–3× the recommended rate causes seedlings to fight for light, water, and nutrients, and most die. If a lawn is thin, fix the cause first (compaction, shade, thatch, poor soil), then overseed at half the new-lawn rate.