Grass Seed Calculator

Calculate the amount of grass seed needed for your lawn based on area, grass type, and whether you are seeding a new lawn or overseeding an existing one.

SEED NEEDED
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Lawn Area
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Seed Rate
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Bags (5 lb)
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Bags (25 lb)
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Grass Seeding Basics

Applying the right amount of grass seed is critical for a healthy, thick lawn. Too little seed results in thin, patchy coverage that allows weeds to establish. Too much seed causes overcrowding, leading to weak plants that are more susceptible to disease and drought stress.

Seeding rates vary significantly by grass species. Fine-bladed grasses like bermuda and zoysia require less seed per square foot because they spread aggressively through stolons and rhizomes. Bunch-type grasses like tall fescue need more seed because each plant stays in place.

Seeding Formula

Seed (lbs) = (Lawn Area in sq ft ÷ 1,000) × Seeding Rate × Application Factor

Seeding Rates by Grass Type

Grass TypeNew Lawn (lbs/1000 sqft)Overseeding (lbs/1000 sqft)Season
Kentucky Bluegrass3 - 41.5 - 2Cool
Tall Fescue6 - 83 - 4Cool
Perennial Ryegrass3 - 41.5 - 2Cool
Fine Fescue4 - 62 - 3Cool
Bermuda Grass1 - 20.5 - 1Warm
Zoysia0.5 - 10.25 - 0.5Warm

Frequently Asked Questions

When is the best time to seed a lawn?

For cool-season grasses (bluegrass, fescue, ryegrass), seed in early fall (September) when soil is warm but air is cooling. For warm-season grasses (bermuda, zoysia), seed in late spring to early summer when soil temperatures exceed 65F.

How long does grass seed take to germinate?

Kentucky Bluegrass: 14-30 days. Tall Fescue: 7-14 days. Perennial Ryegrass: 5-10 days. Bermuda Grass: 10-30 days. Keep the seed moist during germination - light watering 2-3 times daily.

Should I use a seed blend or single species?

Blends of 2-3 compatible species provide better disease resistance and adaptability. A typical cool-season blend might be 50% Kentucky Bluegrass, 30% Perennial Ryegrass, and 20% Fine Fescue.