Seeding rates by grass type
Standard broadcasting rates run 3–5 lbs of seed per 1,000 sq ft for tall fescue and bluegrass blends, less for ryegrass, more for fine fescues. Overseeding an existing lawn uses half the new-lawn rate. The calculator defaults to 4 lbs per thousand — adjust for your variety's bag label, which always states its own rate.
Buy for germination, not just coverage
Seed viability drops with age and deep planting, so the pros seed slightly heavy and roll lightly for soil contact. Water twice daily for the first three weeks — seed that dries during germination is dead, no matter how precisely you measured it.
Sources and standards
Where these figures come from
Every formula on this page is implemented from the published reference material below. Where a value depends on a regional code, the calculator lets you override it rather than assuming one jurisdiction.
- USDA Natural Resources Conservation Service — soil texture, bulk density and seeding rate guidance.
- US Geological Survey — mineral commodity data and aggregate density references.
- National Stone, Sand & Gravel Association — aggregate grading and product specification references.
Figures, formulas and reference tables last verified: 19 September 2026.