How much grass seed do I need per 1,000 square feet?

It depends on the grass: about 3 lb for Kentucky bluegrass, 7 lb for perennial ryegrass, 8 lb for tall fescue and 1 lb for Bermuda per 1,000 sq ft on a new lawn. Overseeding uses about half.

How much seed for a 5,000 sq ft lawn?

At an overseed rate of 4 lb per 1,000: 5,000 × 4 ÷ 1,000 = 20 lb. At a new-lawn rate of 8, it is 40 lb.

Can I use too much grass seed?

Yes. Over-seeding crowds seedlings so they compete for water and light and grow weak and spindly. Match the rate to the job rather than adding extra.

When should I plant grass seed?

Cool-season grasses (fescue, bluegrass, ryegrass) do best in early fall; warm-season grasses (Bermuda, zoysia) in late spring. Timing matters as much as the seed count.

Grass seed calculator: how much seed do I need?

Q: What is the difference between the new-lawn and overseed rate?

Overseeding an existing thin lawn uses about half the new-lawn rate, because the established turf already provides cover. Bare soil uses the full rate.

Grass seed is dosed by pounds per 1,000 square feet, and the right rate depends on your grass type and whether you are seeding bare soil or overseeding a thin lawn. The formula: pounds = area × rate ÷ 1,000.

By Francesco Zinghinì

The seeding-rate formula

Seed bags print a rate in pounds per 1,000 sq ft. To convert that to pounds for your whole lawn:

seed (lb) = area (sq ft) × rate (lb per 1,000 sq ft) ÷ 1,000

The grass-seed calculator takes your area and rate and returns the pounds to buy. If you do not know your lawn area yet, measure it first with the lawn-area estimator.

Worked example: 5,000 sq ft at 4 lb per 1,000

A common tall-fescue mix seeds new lawns at about 8 lb per 1,000 sq ft and overseeds at about 4. For a 5,000 sq ft lawn you are overseeding at 4:

Seed = 5,000 × 4 ÷ 1,000 = 20 lb.

At the new-lawn rate of 8, the same lawn would need 40 lb. Doubling the rate doubles the seed — which is exactly why using the right rate for your situation matters.

Seeding rates by grass type

Rates differ because seed size and germination differ. As labeled planning typicals (always follow the rate on your bag):

Kentucky bluegrass — about 3 lb per 1,000 (tiny seeds, spreads by rhizomes).
Perennial ryegrass — about 7 lb per 1,000 (fast germination, bunch type).
Tall fescue — about 8 lb per 1,000 (larger seed, bunch type).
Bermuda — about 1 lb per 1,000 (very small seed, warm-season spreader).

The full chart, with new-lawn and overseed columns, is in the grass-seed rate table.

New lawn vs. overseeding

Overseeding — sowing into an existing thin lawn to thicken it — uses about half the new-lawn rate, because the established turf already provides cover. Seeding bare soil from scratch uses the full rate. More is not better: over-seeding crowds seedlings, which then compete for water and light and grow spindly. Match the rate to the job.

Warm-season vs. cool-season timing

Seed germinates best when soil temperature suits the grass. Cool-season grasses (bluegrass, ryegrass, fescue) do best sown in early fall, with spring as a second choice. Warm-season grasses (Bermuda, zoysia) prefer late spring into early summer. Sowing at the wrong time is the most common reason a correctly measured seeding fails — the seed count was right, the calendar was wrong.

Feeding and watering the new seed

A new seeding benefits from a starter fertilizer — size it with the fertilizer calculator and read the NPK guide to translate the bag’s numbers into pounds of product. Newly sown seed also needs light, frequent watering to keep the top layer moist until germination; the watering-needs tool turns inches into gallons and run time. Once established, taper to deeper, less frequent watering to drive roots down.

Worked example: a new lawn from bare soil

Say you are seeding a brand-new 3,000 sq ft lawn with a tall-fescue blend at the full 8 lb per 1,000:

Seed = 3,000 × 8 ÷ 1,000 = 24 lb.

If you later overseed that same lawn to thicken it, drop to the 4 lb rate and you need just 12 lb. Buying one 25 lb bag covers the new seeding with a little to spare — handy for the bare patches that always turn up along edges and where the spreader missed.

Getting even coverage with a spreader

The pound count is only right if it actually lands evenly. Split the total in half and apply in two passes at right angles — north-south, then east-west — at half the spreader setting each. This cancels the striping you get from a single pass and covers the turns and edges. Calibrate by weighing the seed before and after a measured strip if you want to be exact; otherwise set the spreader to the bag’s recommendation and lean on the two-pass method.

Soil prep and seed-to-soil contact

Seed germinates where it touches moist soil, not where it sits on thatch or hard ground. For a new lawn, loosen the top inch, rake smooth, sow, then rake lightly again or roll so the seed nestles in. For overseeding, mow low and rake or core-aerate first so seed reaches the soil. A thin topdressing of compost helps hold moisture — size it with the compost calculator. Poor seed-to-soil contact, not a wrong seed count, is the usual reason a seeding comes in patchy.

Common grass-seed mistakes

Using the new-lawn rate to overseed (or vice versa) — you end up crowded or thin.
Sowing at the wrong time of year — the biggest single cause of failure.
Letting the seed dry out before germination — keep the top layer moist with light, frequent watering.
Ignoring the grass type — Bermuda at 1 lb and fescue at 8 lb are not interchangeable rates.

Everything here is a planning estimate — coverage varies by product, so confirm the rate on your seed bag and buy a little extra for bare patches and reseeding.

Key takeaways

Seed (lb) = area × rate (lb per 1,000 sq ft) ÷ 1,000.
Rates differ by grass: about 3 lb bluegrass, 7 lb ryegrass, 8 lb fescue, 1 lb Bermuda per 1,000 sq ft.
Overseeding uses about half the new-lawn rate; bare soil uses the full rate.
A 5,000 sq ft lawn at 4 lb per 1,000 needs 20 lb of seed.
Timing (early fall for cool-season, late spring for warm-season) matters as much as the count.