Free Instant Estimate

Fertilizer Calculator

Find out exactly how much fertilizer you need — and how many bags to buy — based on your product's N-P-K label and desired application rate.

Fertilizer Label (N-P-K)

Enter the three numbers printed on the bag, e.g. a "10-5-5" bag is 10% nitrogen, 5% phosphate, 5% potash.

N (Nitrogen)

P (Phosphate)

K (Potash)

Nitrogen % must be greater than 0 (it's the value you're solving for). Phosphate % must be 0–100. Potash % must be 0–100.

Desired Application & Area

Desired Nitrogen (N) Application Rate

lb/1000ft² lb/acre kg/ha

Enter a valid application rate (0 or more).

Lawn / Field Area (in 1000 sq ft units, e.g. 2.5 = 2,500 sq ft) Enter a valid area (greater than 0).

Fertilizer Bag Weight (optional, lbs — to calculate bags needed) Bag weight cannot be negative.

Estimate ready

Fertilizer Application Rate 0.00

Fertilizer Weight Required 0.00 lbs

You'll need 0 bag(s)

Total P₂O₅

0.00

Total K₂O

0.00

Estimates only. Follow the product label's own instructions and consider a soil test before applying fertilizer.

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