Lawn Feeding Calculator

Pick your grass and climate, enter your lawn size, and get a full nitrogen feeding program: how much to feed, when to feed, and exactly how many pounds of your fertilizer to spread.

About this tool: how lawn fertilizer rates work

The Rest of the Lawn

Watering Scheduler

Inches a week for your grass, season and soil, turned into days a week, minutes per zone, and cycle-and-soak splits that stop runoff.

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Seeding & Overseeding Calculator

Pounds of seed for a new lawn or an overseed, the window to sow it in, and how to water it through the first month.

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Lime Calculator

Whether the lawn needs lime at all, and how many bags of which kind if it does, worked out without a soil test.

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About this tool: how lawn fertilizer rates work

Lawns are fed by nitrogen per area

Recommendations are in pounds of actual nitrogen per 1,000 sq ft, because 5 lb of 26-0-3 and 5 lb of 10-0-4 are not the same feed. One application is 0.5 to 1.0 lb N, and the program above is built to stay inside that: a lawn that wants little nitrogen gets fewer feedings rather than weaker ones, because a lighter pass than that is more than a spreader can lay down evenly.

Turning that into pounds of your bag

Pounds of product for 1 lb of N = 100 ÷ the first number. So 26-0-3 needs 3.8 lb per 1,000 sq ft, and 10-0-4 needs 10 lb for the same job. Halve it for a half-pound feeding.

How much across a year

GrassTypical annual N
Fine fescue1 to 2 lb
Centipede1 to 2 lb
Buffalograss1 to 2 lb
Tall fescue2 to 4 lb
Kentucky bluegrass2 to 4 lb
Perennial ryegrass2 to 4 lb
Zoysia2 to 4 lb
St. Augustine2 to 5 lb
Bermuda3 to 6 lb

Leaving clippings returns a meaningful share of that. Slow-release nitrogen lets you safely apply a higher single rate; straight urea is easy to overdo.

Timing matters as much as amount

Cool-season grass does its best work in autumn: early September and again late October. Heavy nitrogen in summer heat forces growth under stress. Warm-season is the mirror: late spring through summer, stopping a month before frost. Never feed dormant grass.

Why the middle number is often zero

Established lawns rarely need it, and many states restrict it on turf because of runoff. Apply only on a soil test shortfall or at seeding.