Here is the information for figuring our how much fertilizer to use on your lawn.
The first step is to measure each section of your yard. Say the front yard is 25 feet by 40 feet, which is 1000 square feet. On fertilizer bags, there is a series of numbers listed, usually something like 19-9-9. That translates to 19 percent nitrogen, 9 percent phosphorus, 9 percent potash. These numbers are always in percentages. There are some other trace ingredients listed, but they are not important for this formula.
Most recommendations call for one pound or less of actual nitrogen per 1000 square feet of lawn. Let's say you buy a standard sized 40 pound bag of fertilizer. With a 40-pound bag of 19-9-9, you would divide one pound by 19 percent (the percentage of the nitrogen) to get about five and a quarter (5.25) pounds, so you would want to apply about five and a quarter pounds of your bag's fertilizer to cover your 1000 square feet of lawn.
With this calculation, the 40 pound bag of fertilizer will cover about 7600 square feet of lawn, or about 7 applications on your 1000 square foot lawn.
I hope that with this little bit of math you will be able to apply fertilizer more efficiently.
