Seed labels and university extension guides list pounds per 1,000 square feet. New lawns need more seed than overseeding because you are covering bare soil.
Typical ranges: Kentucky bluegrass 2–3 lb new / 1–2 overseed; tall fescue 6–8 / 3–4; perennial rye 5–10 / 3–5; bermudagrass 1–2 / 0.5–1. This tool uses midpoints you can override.
Measure the lawn (or use the square foot calculator) then choose the grass that matches your bag.
Soil for new beds beside the lawn is in the soil calculator, and a gravel edge uses the crushed stone calculator.
How this calculation works
pounds = (sq ft ÷ 1,000) × lb per 1,000 for the selected job.