๐ฑ Gardening
Fertilizer Calculator
The three numbers on a fertilizer bag are the percentages of nitrogen, phosphate and potash by weight. A 10-10-10 bag is ten percent of each, so delivering one pound of actual nitrogen takes ten pounds of product.
How it works
Area to fertilise
Nutrient to target
Target nutrient
N on the bag
P on the bag
K on the bag
Bag weight
Nutrient required
Percentage of that nutrient on the bag
Fertilizer product needed
Bags needed
Application rate
Frequently asked questions
How do I use the Fertilizer Calculator?
Fill in the fields above โ the result recalculates instantly as you type. Everything runs in your browser, so the values you enter are never collected or stored.
Is this calculator free?
Yes. It is completely free, requires no account, and works on phones, tablets and desktops.