Lawn Fertilizer Calculator
How much fertilizer your lawn needs, and how many bags to buy, based on application rate.
Every calculation runs locally in your browser. Application rate is printed on the product label — using the wrong rate can under- or over-fertilize the lawn, so check the specific product you're using.
Bags to buy
2
Total fertilizer needed
30 kg
For informational and educational purposes only — not professional advice, and not a substitute for consulting a qualified professional about your specific situation. TrueMeasureKit is not liable for decisions made based on these results. See our Terms of Service.
Why the label's rate matters more than the lawn's size
Fertilizer application rate — grams per square meter — varies by product depending on its nutrient concentration and intended use (a starter fertilizer for new grass differs from a maintenance feed for an established lawn), which is why it's an input here rather than a fixed assumption. Applying too little under-feeds the lawn; applying too much can scorch grass or run off into waterways, so it's worth reading the specific bag's instructions rather than assuming a generic rate.
Frequently asked questions
How is application rate used to calculate bags needed?
Fertilizer bags list an application rate (like pounds per 1,000 sq ft) on the packaging — this calculator divides your lawn's total area by that coverage rate to determine how many bags you need for even coverage.