Grass Seed & Lawn Calculator
A 5,000 sq ft new tall-fescue lawn needs 40 lb of grass seed + 20 lb of starter fertilizer ($80–$320 in seed). Enter your lawn size and grass type for an exact estimate.
Inputs
Estimate
- Grass seed needed7.5 lb
- Starter fertilizer (10-10-10) needed4 lb of 10-10-10 per 1,000 sq ft at seeding.20.0 lb
- Estimated seed costAverage $5/lb. Premium seed: $7–$15/lb.$38
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Try Remodel AI freeHow to calculate grass seed and fertilizer
Grass seed amounts depend on grass type and seeding purpose. New lawns use the full rate. Overseeding (adding seed to existing lawn) uses about 60% of the new rate. Repair patches need 50% more than new seeding.
Different grass types have very different seeding rates. Kentucky bluegrass has tiny seeds and only needs 1.5 lb per 1,000 sq ft. Tall fescue has large seeds — 8 lb per 1,000 sq ft. Always check the seed bag rate; this calculator uses industry-standard rates.
Apply starter fertilizer (10-10-10 or 16-16-16) at seeding to boost root growth. Standard rate: 4 lb per 1,000 sq ft. Water thoroughly after seeding and keep the seedbed moist for 2–3 weeks until germination.
Formulas used
- Seed pounds
(lawn_area / 1000) × seed_rateSeed rate varies by grass type (1.5–8 lb per 1,000 sq ft) and purpose (new vs overseed).
Frequently asked questions
How much grass seed do I need for 5,000 sq ft?+
Depends on grass type and purpose. New tall fescue: 40 lb. Overseeding bluegrass: 4.5 lb. New Kentucky bluegrass: 7.5 lb. Repair patches with tall fescue: 64 lb. Use the calculator above with your specific grass type.
How much grass seed per 1,000 square feet?+
Kentucky bluegrass: 1.5 lb new / 1 lb overseed. Tall fescue: 8 lb new / 5 lb overseed. Perennial ryegrass: 7 lb new. Bermuda: 2 lb new. Zoysia: 2 lb new. Fine fescue: 4 lb new.
When is the best time to plant grass seed?+
Cool-season grasses (bluegrass, fescue, ryegrass): late August through mid-October. Warm-season grasses (Bermuda, zoysia): May through July. Spring seeding works but fall is better — less competition from weeds and more reliable rainfall.
How much fertilizer do I need for new grass seed?+
Apply 4 lb of starter fertilizer (10-10-10 or 16-16-16) per 1,000 sq ft at seeding. Avoid weed-and-feed products on new seed — they prevent germination.
How much does grass seed cost?+
Budget seed: $2–$4 per lb. Mid-grade: $4–$8 per lb. Premium named cultivars: $7–$15 per lb. A 5,000 sq ft new tall fescue lawn costs $80–$320 in seed alone.