Free Landscape Calculator
Grass Seed Calculator
Calculate exactly how many pounds of grass seed for new lawns and overseeding. Supports Bermuda, Tall Fescue, Kentucky Bluegrass, Ryegrass and Zoysia with correct seeding rates.
👤 Who is this for: new homeowners, lawn renovators & landscaping pros.
📊 Understanding Your Results
Pounds of Seed — Total seed needed based on your lawn area and grass type seeding rate.
25lb Bags — Standard bag size for most grass seed varieties.
Cost Estimate — Based on average US grass seed prices of $3–$8 per pound.
How the Grass Seed Calculator Works
Our grass seed calculator uses the recommended seeding rate for each grass type measured in pounds per 1,000 sq ft. Seeding rates differ significantly between species — using the correct rate ensures proper germination density.
The Grass Seed Formula
Step 2: Pounds Needed = (Area ÷ 1,000) × Seeding Rate
Step 3: Bags = Pounds ÷ Bag Size (round up)
Step 4: Overseeding = New Lawn Rate × 0.5
Example: 5,000 sq ft lawn seeded with Tall Fescue at 7 lbs/1,000 sq ft = 5 × 7 = 35 pounds = 2 bags of 25-lb seed.
Grass Seed Rates by Grass Type
| Grass Type | New Lawn | Overseeding | Climate |
|---|---|---|---|
| Bermuda Grass | 3 lbs/1,000 sqft | 1.5 lbs | Warm / South |
| Tall Fescue | 7 lbs/1,000 sqft | 3.5 lbs | Cool / Transition |
| Kentucky Bluegrass | 2.5 lbs/1,000 sqft | 1.25 lbs | Cool / North |
| Perennial Ryegrass | 5 lbs/1,000 sqft | 2.5 lbs | Cool / Transition |
| Zoysia Grass | 2 lbs/1,000 sqft | 1 lb | Warm / Transition |
📝 Real Project Example
5,000 sq ft new tall fescue lawn:
- Seed needed: 5 × 7 = 35 lbs
- Bags: 35 lbs = two 25-lb bags (50 lbs of seed covers up to ~7,000 sq ft at this rate)
- Same lawn in Kentucky bluegrass: 5 × 2.5 = 12.5 lbs — small seed goes much further
- Cost check: 50-lb tall fescue at ~$100–$150 = ~$125 for the whole lawn
Sow at the recommended rate — not heavier. Crowded seedlings compete, grow weak, and invite disease. Split the seed in two passes (north-south, then east-west) for even coverage.
📚 Sources & Methodology
How we calculate. Step 1: lawn area in square feet. Step 2: seed needed = (area ÷ 1,000) × species rate (e.g. tall fescue 7 lbs, Kentucky bluegrass 2.5 lbs per 1,000 sq ft for new lawns; roughly half for overseeding). Always check the rate on your seed bag — coated seed runs heavier.
Cross-checked. Our rates match cooperative extension seeding guides; the 5x spread between Bermuda and ryegrass comes from seed size, not guesswork.
Sources:
- University of Nebraska Extension — Get Ready for Lawn Seeding (tall fescue 6–8 lbs, KBG 2–3 lbs per 1,000 sq ft)
- NC State Extension — Tall Fescue and Kentucky Bluegrass Home Lawn Calendar (renovation seeding rates)
Last updated: October 2026.
Grass Seed per Acre
One acre is 43,560 sq ft — multiply the per-1,000-sq-ft rate by 43.56. Using the same seeding rates as the calculator above:
| Grass Type | New Lawn (lbs/acre) | Overseeding (lbs/acre) |
|---|---|---|
| Bermuda Grass | 131 | 65 |
| Tall Fescue | 305 | 153 |
| Kentucky Bluegrass | 109 | 54 |
| Perennial Ryegrass | 218 | 109 |
| Zoysia Grass | 87 | 44 |
How much grass seed do I need per acre? For a new lawn: tall fescue about 305 lbs per acre, Kentucky bluegrass about 109 lbs, Bermuda about 131 lbs, perennial ryegrass about 218 lbs and zoysia about 87 lbs. Overseeding takes roughly half. For an exact figure for your lawn, enter its square footage in the calculator above.
Frequently Asked Questions
Common questions about grass seed for new lawns and overseeding.
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Apply seed in two passes at right angles for even coverage.
Keep seedbed moist 2–3× daily until grass is 2 inches tall.
Seed cool-season grass in early fall for best results.
Sowing into bare ground? Seed takes best in 4–6 inches of quality topsoil — work out how much you need with our topsoil calculator.