You enter your lawn's length and width in feet. The calculator multiplies these to find total square footage, then applies your chosen seeding rate (4 lb per 1000 sq ft for new lawns, 2 lb per 1000 sq ft for overseeding). It assumes uniform lawn shape and that rates are approximate; actual needs depend on soil quality, climate, and grass type.
Seeding rates vary significantly by grass species (fescue, bluegrass, ryegrass, bermuda), seed purity, and germination rates. This calculator uses standard industry recommendations—always check your seed bag's label for the rate specific to that product and follow the manufacturer's guidance.
Buy at least the calculated amount, rounded up to whole bags. Many lawn care professionals recommend buying 10–15% extra to account for spillage, seeding gaps, and future touch-ups. The calculator rounds up to the nearest 5-lb bag to help with this.
Yes. Overseeding (2 lb per 1000 sq ft) is designed for sparse or thin areas in established lawns. If more than 50% of your lawn is bare, consider using the new lawn rate (4 lb per 1000 sq ft) for those sections, or consult a local extension service for guidance.
This calculator uses seeding rates that work across common cool-season grasses (fescue, bluegrass, ryegrass) and warm-season types (bermuda). Check your local university extension service or seed supplier for species-specific rates if you want to optimize further.
This calculator assumes a rectangular lawn. For irregular shapes, divide your lawn into rectangles, calculate each section, and add the results together. Or estimate an average length and width that approximates your total area.
The best timing depends on your grass type and climate. Cool-season grasses seed best in early fall or spring; warm-season types seed in late spring or early summer. Consult your local extension office for the ideal window in your region.
Estimate only. Results reflect your inputs and standard formulas. Double-check important decisions independently.