Lawn care math, in plain english

Free lawn calculators in plain english. How much fertilizer, seed, or water your actual lawn needs — every tool is free, instant, and explains itself. No agronomy degree required.

The number every other answer depends on

Every bag of fertilizer, seed, and lime doses by your lawn's square footage — and most people are guessing theirs. Measure it once with the lawn size calculator (odd shapes welcome), write it down, and every tool on this site gets accurate.

The Basics

Lawn Size CalculatorMeasure your lawn once — every fertilizer and seed number depends on it.

Feeding & Seeding

Lawn Fertilizer CalculatorYour bag's N-P-K numbers turned into pounds to actually spread.Grass Seed CalculatorSeed pounds by grass type — new lawn and overseeding rates differ 2×.Lawn Lime CalculatorYour soil pH turned into lime pounds — or an honest 'skip it.'

Watering & Mowing

Lawn Watering CalculatorYour sprinkler's real output turned into minutes per session.Mowing Height GuideDeck height by grass type, and the one-third rule for timing.

Weeds & Problems

Spray Mix CalculatorYour label's rate turned into exact ounces per tank load.

Projects & Costs

Mulch CalculatorYards, bags, and the bulk-vs-bagged break-even for your beds.Sod CalculatorPallets + rolls to order, and what the instant-lawn premium costs.Topsoil CalculatorYards, bags, and tons — and the point where delivery beats the trunk.

Why these calculators?

Lawn advice comes in two flavors: university extension PDFs written for turf professionals, and product marketing that just says 'apply liberally.' The actual math — pounds of nitrogen per 1,000 square feet, seed rates by grass type, watering minutes by sprinkler output — is simple once someone shows it plainly. That's what LawnCareKit does: your numbers, the formula visible, and what to do next.