How to use this grass seed calculator
- Measure your lawn area.
- Choose the grass type on your seed bag.
- Select new lawn or overseeding (about half the rate).
- Always check the rate printed on the bag: blends vary.
Example
A new 60 × 40 ft lawn (2,400 sq ft (223 m²)) seeded with tall fescue at about 7 lb per 1,000 sq ft needs 16.8 lb of seed.
What to know before you buy
Cool-season and warm-season grasses
Cool-season grasses such as tall fescue, Kentucky bluegrass and ryegrass grow best in northern regions and are seeded in early fall. Warm-season grasses such as Bermuda, zoysia and centipede suit the South and are seeded in late spring once soils are warm.
Overseeding an existing lawn
Overseeding thickens a thin lawn. Mow short, rake or core-aerate to expose the soil, spread seed at about half the new-lawn rate and keep the surface moist until the new grass is established.
Seed for 1,000 sq ft by grass type
| Grass type (new lawn) | Seed needed | Kilograms |
|---|---|---|
| Kentucky bluegrass | 2.5 lb | 1.13 kg |
| Tall fescue | 7 lb | 3.18 kg |
| Perennial ryegrass | 7.5 lb | 3.4 kg |
| Fine fescue | 4 lb | 1.81 kg |
| Bermuda (hulled) | 1.5 lb | 0.68 kg |
| Sun & shade mix | 5 lb | 2.27 kg |
Formula
Seed (lb) = area ÷ 1,000 × seeding rate per 1,000 sq ft. Overseeding uses about half the new-lawn rate.
Tips from the pros
- Rake the soil lightly after seeding so the seed makes good contact with the soil.
- Keep the top layer moist with light, frequent watering until the grass is about 2 inches tall.
- Spread half the seed in one direction and half at a right angle for even coverage.
Common mistakes to avoid
- Seeding too heavily: overcrowded seedlings compete and become weak.
- Applying pre-emergent weed control at the same time, which also stops grass seed from germinating.
Frequently asked questions
How much grass seed per 1,000 square feet?
From 1–2 lb for Bermuda to 6–8 lb for tall fescue and ryegrass.
When is the best time to seed?
Early fall for cool-season grasses, late spring to early summer for warm-season grasses.
How much grass seed for 1,000 square feet?
From 1–2 lb for Bermuda to 6–8 lb for tall fescue and perennial ryegrass for a new lawn.
How long does grass seed take to grow?
Ryegrass sprouts in 5–10 days, tall fescue in 7–14 days and Kentucky bluegrass in 14–30 days.