Grass seed is sold by weight, and seeding rates are given as pounds for a set area of lawn, such as 2 lb per 1,000 sq ft for Kentucky bluegrass on a new lawn. For a seed blend, the rate on the bag governs.
How to use this calculator
- Measure the lawn's length and width in feet. For an irregular yard, split it into rectangles, work out each one and add the pounds together.
- Leave out beds, patios, driveways and the house footprint, since those areas take no seed.
- Pick the job. Use New lawn for bare soil and Overseeding for turf that is already growing, because the rate changes with the job.
- Pick the grass that matches your bag. If the bag is a blend, follow its label instead of the rate on this page.
- Divide the pounds by the bag weight printed on the label, then round up to a whole bag.
Worked examples
Front lawn
Lawn: 60 × 35 ft · Grass: Tall fescue
- Grass seed
- 12.6 lb
- Seeding rate
- 6.0 lb per 1,000 sq ft
- Lawn area
- 2,100 sq ft
Backyard overseeding
Lawn: 80 × 50 ft · Grass: Kentucky bluegrass · Job: Overseeding
- Grass seed
- 6.0 lb
- Seeding rate
- 1.5 lb per 1,000 sq ft
- Lawn area
- 4,000 sq ft
Bermuda lawn
Lawn: 40 × 30 ft · Grass: Bermudagrass (hulled)
- Grass seed
- 1.8 lb
- Seeding rate
- 1.5 lb per 1,000 sq ft
- Lawn area
- 1,200 sq ft
Ryegrass patch overseeding
Lawn: 30 × 25 ft · Grass: Perennial ryegrass · Job: Overseeding
- Grass seed
- 3.8 lb
- Seeding rate
- 5.0 lb per 1,000 sq ft
- Lawn area
- 750 sq ft
Pounds of seed for new lawns of common sizes, by grass
| Lawn size | Grass: Kentucky bluegrass | Grass: Tall fescue | Grass: Bermudagrass |
|---|---|---|---|
| 20 × 30 ft | 1.2 | 3.6 | 0.9 |
| 50 × 40 ft | 4.0 | 12.0 | 3.0 |
| 60 × 80 ft | 9.6 | 28.8 | 7.2 |
| 100 × 100 ft | 20.0 | 60.0 | 15.0 |
Each cell: Grass seed (lb). Inputs not in the table use the calculator's starting values.
How the calculation works
Length times width gives the lawn area in square feet. The calculator scales the seeding rate for your grass and job to that area, and shows the seeding rate and lawn area beside the answer so you can check it.
The sourced range for Kentucky bluegrass on a new lawn is 1 to 3 lb per 1,000 sq ft, so read the result as an estimate.
Bermudagrass rates refer to hulled seed, the kind with its outer hull removed. The new-lawn rate is 1.5 lb per 1,000 sq ft. If your bag is not hulled, follow its label.
New lawn or overseeding?
A new lawn is sown onto bare soil, and overseeding goes into turf that is already growing, so each job has its own rate. For Kentucky bluegrass the new-lawn rate is 2 lb per 1,000 sq ft and the overseeding rate is 1.5 lb per 1,000 sq ft.
Overseeding rates are published here only for Kentucky bluegrass, tall fescue and perennial ryegrass. For the other grasses, the calculator tells you to follow the seed label, which is the safest guide for any overseeding job.
Mistakes to avoid
- Setting the wrong job. Choose the job before you read the result, because the overseeding rate is a separate number.
- Assuming a bag holds the grass you picked. Bags of the same weight can hold different grasses, so read the label first.
- Missing side strips. Narrow areas along a drive or fence are easy to leave out, so measure each one as its own rectangle.
- Treating the answer as exact. It is an estimate from typical rates, so the label on your bag and your spreader settings come first.
Seed or sod?
If you are weighing seed against laid turf, run the same lawn through the sod calculator. Sod is sold in pieces and pallets rather than pounds, so the two results do not compare directly.
The fertilizer calculator uses the same length and width, so you can size feeding for the same lawn.
How much grass seed per thousand square feet?
The rate depends on the grass and on whether you start a new lawn or overseed. For a new lawn: Kentucky bluegrass 2 lb per 1,000 sq ft, tall fescue 6 lb per 1,000 sq ft (usual range 6 to 8 lb per 1,000 sq ft), perennial ryegrass 4.5 lb per 1,000 sq ft, fine fescue 4.5 lb per 1,000 sq ft, hulled bermudagrass 1.5 lb per 1,000 sq ft, zoysiagrass 1.5 lb per 1,000 sq ft and centipedegrass 0.375 lb per 1,000 sq ft. For overseeding: Kentucky bluegrass 1.5 lb per 1,000 sq ft, tall fescue 4 lb per 1,000 sq ft and perennial ryegrass 5 lb per 1,000 sq ft. If your bag lists a different rate, follow the bag.
How to prepare the soil and care for new seed
Rake the area loose and level before you sow, then spread the seed evenly so it touches the soil. After seeding, keep the top of the soil moist with about 2 light waterings a day for 3 weeks, and add more on hot, windy days. Bermudagrass usually sprouts in 7 to 10 days and fine fescue in 5 to 12 days.
Common questions
What grass seed do I need?
That depends on your climate, how much sun the lawn gets and how much foot traffic it takes. The calculator lists each species with its own rate, so pick the grass on your bag, or ask your local extension office which grasses suit your area.
Can you just throw grass seed and it will grow?
Not reliably. Seed needs contact with soil, and a light, uneven scatter leaves gaps where weeds can take hold. Use the rate for your job and spread the seed evenly over the whole area.
Can I use this rate for a seed blend?
Use the rate on the bag instead. This page gives rates for individual species, so a blend's label governs the amount.
How much area does a bag of grass seed cover?
A bag covers its weight divided by the seeding rate for your grass, so the answer changes with the grass and the job. For example, Kentucky bluegrass on a new lawn uses 2 lb per 1,000 sq ft, while tall fescue uses 6 lb per 1,000 sq ft, so the same bag covers a much smaller area of fescue. Check the bag label first, because a blend has its own rate.