Grass Seed Calculator
Determine the right amount of grass seed for your lawn project. Whether you are starting from bare soil or thickening an existing lawn, this calculator gives you pounds of seed needed, bags to buy, and total cost.
Seeding Rates by Grass Type
Different grass species require different seeding rates. Kentucky bluegrass needs 2 to 3 pounds per 1,000 square feet for new lawns. Tall fescue requires 6 to 8 pounds, and perennial ryegrass needs 8 to 10 pounds. Bermuda grass uses 1 to 2 pounds of hulled seed per 1,000 square feet. For overseeding, cut these rates roughly in half. Always check the seed bag label for the manufacturer's recommended rate, as it varies by cultivar and blend.
Tips for Successful Seeding
Start with a soil test to determine pH and nutrient needs. Prepare the seedbed by loosening the top inch of soil and removing debris. Apply a starter fertilizer high in phosphorus to encourage root growth. Spread seed evenly using a broadcast spreader, making two passes in perpendicular directions for uniform coverage. Lightly rake the seed into the soil and apply a thin layer of straw mulch to retain moisture. Water lightly 2 to 3 times daily until germination, then gradually reduce frequency while increasing depth.
Frequently Asked Questions
How much grass seed per 1,000 square feet?
For a new lawn, use 6 to 8 pounds per 1,000 square feet for most grass types. Overseeding requires 3 to 4 pounds per 1,000 square feet.
When is the best time to plant grass seed?
Cool-season grasses grow best when seeded in early fall (September). Warm-season grasses should be planted in late spring to early summer when soil temperatures stay above 65°F.
How long does grass seed take to grow?
Most grass seed germinates in 7 to 21 days depending on the species. Perennial ryegrass sprouts fastest (5 to 10 days), while Kentucky bluegrass can take 14 to 30 days.