Grass Seed Calculator
Enter your lawn size and grass type to get the pounds of seed you need — for a brand-new lawn or overseeding thin turf.
Overseeding into existing turf uses about half the new-lawn rate.
How it works
Each grass species has a standard seeding rate per 1,000 square feet — bluegrass seed is tiny (3 lb covers what takes 8 lb of tall fescue). We multiply your area by that rate, and halve it for overseeding since existing turf fills part of the canopy.
Formula: Seed (lb) = Area ÷ 1000 × rate per 1000 ft² × (½ if overseeding)
Good for
- Seeding a new lawn from bare soil
- Overseeding thin or patchy turf
- Fall renovation projects
- Shade or drought-specific reseeding
Tips
- More seed is not better — overdosing causes seedlings to compete and damp off.
- Cool-season grasses (bluegrass, fescue, rye) establish best in early fall.
- Keep the top ½″ of soil consistently moist until germination — light watering 2–3× daily.
- Check the label: seed mixes state their own rate, which overrides species defaults.
References
Estimates use standard industry volume math. Cross-check your numbers against the pros:
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Open calculator →Grass Seed Calculator FAQ
How much grass seed do I need for 1,000 square feet?
It depends on species: about 3 lb of Kentucky bluegrass, 5 lb of fine fescue, 8 lb of tall fescue, 9 lb of perennial ryegrass, or 1.5 lb of hulled Bermuda for a new lawn. Overseeding uses roughly half those rates.
Can I just spread extra seed for a thicker lawn?
No — seeding far above the recommended rate crowds seedlings, which then compete for light and water and are more prone to disease. Hit the rate, then water well.
When is the best time to seed?
Early fall for cool-season grasses (soil is warm, weeds fade, rain returns) and late spring for warm-season grasses like Bermuda. Spring seeding of cool-season lawns works but fights more weeds.