Lawn Fertilizer Calculator
Calculate how many bags of fertilizer you need per application and per year, with a seasonal schedule and annual cost.
Results
Visualization
How It Works
Keeping your lawn green requires regular fertilizer applications. This calculator figures out how many bags you need per feeding and per year based on your lawn size and the coverage area listed on the bag, then gives you a seasonal schedule.
The Formula
Bags Per Application = ceil(LawnSize / BagCoverage); Annual Bags = BagsPerApp x Applications
Variables
- LawnSize — Your lawn area in square feet
- BagCoverage — Square feet one bag covers (listed on label)
- Applications — Number of times you fertilize per year (4 is standard)
Example
A 5,000 sqft lawn with bags covering 5,000 sqft at $25 each, 4 times per year: 1 bag per application, 4 bags per year, $100 annual cost.
Tips
- Get a soil test before your first application -- it costs $15-25 and tells you exactly what your lawn needs.
- Never apply fertilizer to frozen or dormant grass -- it will wash away and pollute waterways.
- Water your lawn within 24 hours of applying granular fertilizer to activate it.
- A mulching mower returns clippings to the lawn, providing up to 25% of its nitrogen needs for free.
- Over-fertilizing causes more problems than under-fertilizing -- brown patches, thatch buildup, and runoff pollution.