Seeding rates
Seed needed = (lawn sq ft ÷ 1000) × rate. Cool-season blends often use about 3–4 lb/1000 sq ft for new lawns and roughly half that for overseeding. Species differ—tall fescue, Kentucky bluegrass, and ryegrass labels vary, so prefer the bag rate when it conflicts with defaults.
Worked example
A 50 × 20 ft yard is 1,000 sq ft. At 3.5 lb/1000 for a new lawn you need 3.5 lb of seed. Overseeding the same lawn at 1.75 lb/1000 needs 1.75 lb. Split large bags across multiple passes for even coverage.
| Job | Cool-season blend | Warm-season (example) |
|---|---|---|
| New lawn | ~4–8 lb | Follow sod/seed tag |
| Overseed | ~2–4 lb | Often lower than new |
Timing and soil
Match species to sun, shade, and your region’s cool- or warm-season window. Topdressing with a light soil mix can improve seed-to-soil contact—estimate soil with the topsoil calculator if you are spreading a wider dressing.
Common mistakes
- Seeding without soil contact (seed on thatch).
- Mowing new seedlings too early.
- Ignoring irrigation during establishment.
Assumptions and limits
The grass seed calculator results are planning estimates for rectangular or cylindrical shapes with uniform depth. Real sites have slopes, voids, and product variation. Always confirm coverage with the manufacturer label and local building practices before you buy large quantities.
Unit toggles switch input labels between US imperial and metric. Shareable URLs store your inputs in the query string for convenience, while the canonical tag stays on the clean page URL so search engines do not index every parameter combination.
Shopping checklist
- Write down the calculator outputs (volume, bags, or piece counts) and round up for waste.
- Call your supplier for density, dye lot, or delivery minimums when ordering bulk material.
- Check access for trucks, wheelbarrows, and staging space before delivery day.
- Photograph existing conditions so you can revisit dimensions if a helper measures differently.
After seeding, keep the surface evenly moist through establishment; the calculator only sizes seed, not water or starter fertilizer.
FAQ
Can I use new-lawn rates for overseeding?
Usually no—overseeding rates are lower. Too much seed increases competition and waste.
Related guides
Sources
- Penn State Extension – Turfgrass Used for: Cool-season turf seeding context; override with bag rate for your mix. Checked .
Estimates only—confirm bag yields on the product label and check local building codes before you pour or order. Not affiliated with QUIKRETE, Sakrete, Sonoco, or any manufacturer named in the sources. Found an error? Tell me.
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