Lawn Fertilizer Calculator

Calculate how much fertilizer to spread on a lawn for a target nitrogen rate and how many bags to buy, free online.

Lawn area

Area unit

Nitrogen rate (lb N per 1,000 sq ft)

Fertilizer nitrogen content (% N, first number)

Bag size (lb)

Price per bag — optional (optional)

About this calculator

Lawns are fertilised by nitrogen rate: usually 0.5–1 lb of actual N per 1,000 sq ft per application. Pounds of product = (lb N wanted × area ÷ 1000) ÷ (fertilizer N% ÷ 100). A bag labelled 24-0-6 contains 24% nitrogen. Don't exceed 4 lb N per 1,000 sq ft a year.