Fertilizer Calculator
How much fertilizer do you need? Enter your lawn size and bag coverage.
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Lawn area—
Estimated cost—
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How this calculator works
Fertilizer bags state the area they cover (e.g. 5,000 sq ft). The calculator divides your lawn area by that coverage and rounds up to whole bags.
Worked example — a 60 ft × 40 ft lawn, 5,000 sq ft per bag:
2,400 sq ft ÷ 5,000 = 1 bag.
Measure only the grass
Subtract the house, driveway and beds — fertilize only the actual lawn area so you don’t over-apply (which can burn the grass).
Frequently asked questions
How much fertilizer for my lawn?
Divide your lawn’s square footage by the coverage printed on the bag.
Can I use too much fertilizer?
Yes — over-applying can burn the lawn and pollute runoff. Stick to the labeled rate.
Planning a landscaping project
Measure each section separately when a bed or lawn is not a perfect rectangle, then add the sections together. Depth, moisture, compaction, and the way a supplier loads material can change the final quantity, so use the result as a purchasing estimate and confirm the supplier's coverage information.
How to use this estimate
- Measure the project in the units shown and recheck your measurements before ordering.
- Use the waste allowance as a planning buffer, not as a substitute for a detailed material takeoff.
- Compare the result with the package yield, coverage, or weight listed by your supplier.
- Prices are user-entered estimates and may change by location, product, delivery, and season.
Accuracy and limitations
Calculapedia provides educational planning estimates. It does not inspect your site, select products, guarantee quantities, or replace a contractor, engineer, architect, building official, or supplier. Confirm the final quantity and any safety or code requirements before buying or building.