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Grass Seed Calculator

For a new lawn, seed at about 8 to 10 pounds of tall fescue per 1,000 square feet, 6 to 9 for perennial ryegrass, 4 to 6 for fine fescue, 2 to 3 for Kentucky bluegrass, or 5 to 7 for a sun and shade mix. To overseed an existing lawn, use half those rates. A 5,000 sq ft new tall fescue lawn works out to roughly 45 pounds of seed.

Updated July 29, 2026 · rates from university extension guidance

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What are you seeding?

Pounds per 1,000 sq ft for a new lawn, from university extension rates.

New lawn or overseeding?

More seed is not more lawn. Sown too heavily, seedlings compete with each other for water and light and the stand comes in thin exactly where you doubled up. Stay near the rate.

In Northeast Ohio the best window is mid-August through late September — warm soil, cooler air, and fewer weeds competing. Spring works but is second best; the seedlings hit summer heat young. Dormant seeding in late fall is a gamble that sometimes pays.

Seeding rates, explained

Why the rates differ so much

It is seed size, not quality. Kentucky bluegrass seed is tiny — a pound of it holds something like a million seeds, where a pound of tall fescue holds a couple of hundred thousand. Sowing bluegrass at a fescue rate would put down several times the seedlings per square foot. The rate is really a seed count in disguise.

Overseeding is half, and only half

Broadcasting seed into a lawn that already exists means every seedling competes with established grass that has a root system and a head start. The standard guidance is 50% of the new-lawn rate, and going heavier does not change the outcome much — the limit is light and water at the soil surface, not how much seed you bought.

Soil first, seed second

Seed needs something to root into. On bare ground or after a regrade, 3 inches of topsoil is a normal seedbed — about 9.3 cubic yards per 1,000 square feet. That is usually the expensive half of a new lawn, which is why it is worth checking whether someone near you is giving topsoil away before you order a load. Work it out on the dirt calculator, then look at the map.

Seeding rate by grass type

GrassNew lawnOverseeding
Tall fescue8–10 lb4–5 lb
Perennial ryegrass6–9 lb3–4.5 lb
Fine fescue4–6 lb2–3 lb
Kentucky bluegrass2–3 lb1–1.5 lb
Sun & shade mix5–7 lb2.5–3.5 lb

Pounds per 1,000 square feet.

Common questions

How much grass seed do I need per 1,000 square feet?
It depends on the grass. For a new lawn: tall fescue 8 to 10 pounds per 1,000 square feet, perennial ryegrass 6 to 9 pounds per 1,000 square feet, fine fescue 4 to 6 pounds per 1,000 square feet, Kentucky bluegrass 2 to 3 pounds per 1,000 square feet, and a typical sun and shade mix 5 to 7 pounds per 1,000 square feet. Bluegrass is lowest because the seed is tiny — a pound of it contains far more seeds than a pound of fescue.
How much seed do I need to overseed an existing lawn?
Half the new-lawn rate. Overseeding tall fescue into existing turf runs about 4 to 5 pounds per 1,000 square feet, and a sun and shade mix about 2.5 to 3.5 pounds per 1,000 square feet. Seed broadcast into established grass competes with it, so doubling the rate does not double what survives.
How much grass seed do I need for a quarter acre?
A quarter acre is about 10,890 square feet, so roughly eleven times the per-1,000 rate. For a new tall fescue lawn that is about 98 pounds at the midpoint — call it two 50-pound bags. For overseeding the same area, about half that.
Can I use too much grass seed?
Yes, and it is a common mistake. Sown too heavily, seedlings compete with each other for water and light, and the stand comes in thin and weak exactly where you doubled up. More seed is not more lawn — stay near the rate.
When should I plant grass seed in Ohio?
Mid-August through late September is the best window in Northeast Ohio: the soil is still warm enough for fast germination, the air is cooling, and there is less weed pressure. Spring seeding works but is second best, because the young grass meets summer heat before it is established.
Do I need topsoil before seeding?
On bare ground or after a regrade, yes — seed needs something to root into. About 3 inches of topsoil is a normal seedbed, which works out near 9.3 cubic yards per 1,000 square feet. Over an existing lawn you are overseeding, not rebuilding, and you do not need a layer of soil first.
How many pounds of grass seed are in a bag?
Shelf bags are commonly 3, 5, 7, 10, 20, 25, or 50 pounds. Work out the pounds you need first and then pick the bag, rather than buying a bag and guessing how far it goes — and round up, because running short partway through a lawn wastes the whole seeding window.
What is the best grass seed for Northeast Ohio?
Turf-type tall fescue is the workhorse for full sun here — it handles heat and drought better than the alternatives and stays green through a dry August. Fine fescue is the shade option, perennial ryegrass germinates fastest when you need cover quickly, and Kentucky bluegrass spreads and repairs itself but is slow to establish.

Need the topsoil first?

On Dirtly the dirt itself is usually free or cheap — you're only solving the moving. Check what neighbors have before you price a delivery.

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