Fertilizer Rate Calculator
Fertilizer is sold as a product with its nutrient share printed on the bag, such as 46 percent nitrogen. This shows how much product covers a field at the nutrient rate you choose.
- Free
- Works offline after your first visit
- Saves on this device
- No sign-up
- Updated
How it works
The nutrient you need is the field size times the rate per acre. The product to buy is that amount divided by the nutrient share, because a bag holds only part of its weight as nutrient.
Enter the rate in pounds of nutrient per acre. Soil test reports and crop guides list these rates. If your rate is per hectare, convert it to pounds per acre first.
Worked example
For a field of 10 ac at 120 pounds of nutrient per acre, with bags that are 46% nutrient, buy 2,609 lb of product.
Questions
Where do I find the rate?
Soil test reports and crop guides list rates for each crop. Follow the rate your agronomist or seed dealer gives you.
Why does the product weigh more than the nutrient?
The bag is mostly carrier material. A product that is 46 percent nitrogen holds 46 pounds of nitrogen in each 100 pounds of product.
Should I add a little extra?
Spreaders can miss or overlap. Many growers run a calibration pass first instead of adding extra by guess.
More like this
- Lawn Fertilizer CalculatorProduct weight from the label rate.
- Acre CalculatorAcres from the length and width of a plot.
- Farm Loan CalculatorPayment and total interest on a farm loan.
- Average Daily Gain CalculatorWeight gained per day between two weighings.
- Chicken Feed CalculatorFeed amount, cost and cost per dozen eggs.
- Drip Irrigation CalculatorEmitter count and total flow for rows.