How to use this calculator
Enter your lawn area in square feet or provide the length and width and let the calculator find the area for you. Select your grass seed type and choose whether you are planting a new lawn or overseeding an existing one.
The calculator shows the recommended range of seed in pounds, how many standard bags you need (5 lb and 25 lb options), and an approximate cost range based on typical retail pricing for that grass type.
Seeding rate guide
| Grass Type | New Lawn | Overseeding | Germination |
|---|---|---|---|
| Kentucky Bluegrass | 2 to 3 lbs / 1,000 sq ft | 1 to 1.5 lbs | 14 to 30 days |
| Bermuda | 1 to 2 lbs / 1,000 sq ft | 0.5 to 1 lb | 10 to 30 days |
| Fescue | 6 to 8 lbs / 1,000 sq ft | 3 to 4 lbs | 7 to 14 days |
| Ryegrass | 8 to 10 lbs / 1,000 sq ft | 4 to 5 lbs | 5 to 10 days |
| Zoysia | 1 to 2 lbs / 1,000 sq ft | 0.5 to 1 lb | 14 to 21 days |
Frequently asked questions
When is the best time to plant grass seed?
Cool season grasses (bluegrass, fescue, ryegrass) perform best when planted in early fall, around September to mid-October. Warm season grasses (bermuda, zoysia) should go down in late spring when soil temperatures stay above 65 degrees consistently.
How much grass seed do I need per square foot?
It depends on the grass type. Fine seeds like bluegrass need only 2 to 3 pounds per 1,000 square feet, while larger seeds like ryegrass need 8 to 10 pounds per 1,000 square feet. Overseeding uses about half the new lawn rate since existing grass is already in place.
What is the difference between overseeding and starting a new lawn?
A new lawn involves seeding bare or freshly prepared soil at full rate. Overseeding means spreading seed over an existing lawn to fill thin spots or introduce improved varieties. Since existing grass already covers much of the area, overseeding uses roughly half the seed.
How long does grass seed take to grow?
Germination ranges from 5 days (ryegrass) to 30 days (bluegrass and bermuda). You will see a full, established look in 6 to 8 weeks, but the lawn needs an entire growing season to develop a deep, mature root system.