Estimate how much fertilizer to apply to a garden, raised bed, lawn area, flower bed, or container garden. Calculate fertilizer pounds, ounces, NPK nutrients supplied, bags needed, cost, and coverage based on garden area, application rate, and fertilizer analysis.
Area and rate mode:
The calculator uses your garden area and fertilizer application rate to estimate total fertilizer needed.
Nitrogen target mode:
The calculator uses your target nitrogen rate and fertilizer nitrogen percentage to estimate how much fertilizer to apply.
Bag coverage mode:
The calculator uses fertilizer bag coverage to estimate how many bags are needed for the area.
Cost mode:
The calculator estimates bags required, seasonal fertilizer amount, cost per application, and total seasonal cost.
A fertilizer calculator helps estimate the right amount of fertilizer for a garden, raised bed, lawn area, flower bed, or container area.
It can help prevent over-application, estimate fertilizer costs, compare NPK products, plan seasonal applications, and determine how many bags to buy.
Your result shows fertilizer pounds and ounces needed, bags required, nitrogen supplied, phosphorus supplied, potassium supplied, application cost, seasonal cost, and coverage based on the fertilizer label and selected application method.
Measure the area, choose an application rate, then multiply the area by the rate. If using a nutrient target, divide the target nutrient amount by the fertilizer nutrient percentage.
N-P-K shows the fertilizer analysis: nitrogen, phosphate, and potash percentages by weight.
Multiply fertilizer pounds by the nitrogen percentage as a decimal. For example, 10 pounds of 10-10-10 contains about 1 pound of nitrogen.
Divide the fertilizer pounds needed by the bag weight, or divide the area by the coverage listed on the fertilizer bag. Round up to buy whole bags.
No. This is an estimate. Actual fertilizer needs vary by soil test results, crop type, fertilizer form, soil texture, irrigation, weather, organic matter, and local growing conditions.