Lawn care planning

Lawn Fertilizer Calculator

Estimate the fertilizer product and bag count needed to meet a nitrogen application target.

Use a soil-test or local-extension recommendation.

Your estimate will appear here

Enter your project details and calculate for a practical planning estimate.

How this estimate works

  • Nitrogen required = lawn area ÷ 1,000 × target pounds of nitrogen per 1,000 sq ft.
  • Product pounds = nitrogen required ÷ (nitrogen percentage ÷ 100). Phosphate and potash are product pounds multiplied by their respective label percentages.
  • Bag count is rounded up because fertilizer is normally purchased in whole bags.

Before you begin

  • This is a planning estimate, not a nutrient recommendation or soil test.
  • Label phosphorus and potassium are reported as P₂O₅ and K₂O equivalents, not elemental P and K.
  • It does not account for slow-release fraction, existing soil nutrients, weather, or local application restrictions.

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