Lawn Calculator
How much grass seed to buy, how much fertilizer to spread, and the right week to do each for your lawn, worked from extension-service rates and your station's frost dates.
Set your place for the best week to seed and feed.
Seeding rates and timing
Seed quantity is your lawn area times the seeding rate for your grass, in pounds per thousand square feet. New lawns need the full rate; overseeding an existing lawn takes about half. Cool-season grasses go down best in late summer, roughly six to eight weeks before your first fall frost, when the soil is still warm but nights have cooled and weed pressure has dropped. Spring, just after your last frost, is the second-best window.
Rates follow university extension guidance and are a planning estimate. Read your seed or fertilizer label, which governs.