Grass Seed
Calculator

Seeding rate depends heavily on whether you're establishing a new lawn or overseeding an existing one. New lawns typically need 15-20 lbs of seed per 1,000 sq ft, while overseeding only needs 3-6 lbs per 1,000 sq ft since you're filling gaps, not starting from bare soil.

Seed size and germination rate vary widely by species. Fine fescues have small seeds and need less weight per area, while larger-seeded grasses like ryegrass need more weight to achieve the same seed count per square foot.

Yes, overseeding too densely causes seedlings to compete for light, water, and nutrients, which weakens the whole stand and can lead to thin, spindly growth rather than a thicker lawn. Following the calculated rate produces stronger turf than doubling up.

No, it calculates based on flat area alone. For slopes, add 10-20% more seed since runoff during watering carries some seed away, and for heavy shade, use a shade-tolerant seed blend since standard mixes germinate poorly there regardless of rate.

Most cool-season grasses germinate in 7-14 days and are ready for a first light mowing in about 3-4 weeks, though full establishment and a dense, mature stand takes a full growing season.