Lawn Fertilizer Calculator
Enter your lawn size in the selected unit.
Select the unit of your lawn area.
Select your grass type to use a recommended nitrogen rate.
Select the fertilizer type to adjust nutrient conversion.
Calculated fertilizer amount based on your inputs.
Enter the cost of fertilizer per pound.
Estimated total cost for your fertilizer application.
Created by James S. Lockwood
With a background in botany and ecological sciences, James specializes in creating practical tools and resources to help gardeners, farmers, and plant enthusiasts optimize their green spaces.
Are you struggling to determine how much fertilizer your lawn needs? Our Lawn Fertilizer Calculator makes it easy! Simply enter your lawn size, grass type, and preferred fertilizer type to get instant recommendations for the right amount of fertilizer.
Proper lawn fertilization ensures healthy, green grass, strong root growth, and optimal nutrient absorption. Whether you have Kentucky Bluegrass, Bermuda Grass, Zoysia, or Tall Fescue, our fertilizer calculator for lawns helps you apply the right nutrients at the correct rate.
Table of Contents
How Much Fertilizer Does My Lawn Need?
A healthy lawn requires precise fertilization based on grass type and seasonal needs. The general formula for determining lawn fertilizer requirements is:
Fertilizer Needed (lbs) = (Lawn Area × Target N Rate) ÷ Nitrogen % in Fertilizer
Where:
- Lawn Area = Total area in square feet
- Target N Rate = Recommended nitrogen application per 1,000 sq ft
- Nitrogen % = Percentage of nitrogen in your chosen fertilizer (e.g., Urea 46-0-0 has 46% nitrogen)
For example:
-
A 5,000 sq ft lawn using a 10-10-10 fertilizer (10% Nitrogen) with a recommended 4 lbs N per 1,000 sq ft would require:
(5 × 4) ÷ 0.10 = 200 lbs of 10-10-10 fertilizer
Use the Lawn Fertilizer Calculator above to calculate the exact amount of fertilizer required.
Calculate Fertilizer Application for Grass
Different grass types require different amounts of nitrogen per year. Below is a quick guide:
Kentucky Bluegrass
🌿 3 - 5 lbs of Nitrogen
Bermuda Grass
🌿 4 - 6 lbs of Nitrogen
Tall Fescue
🌿 2 - 4 lbs of Nitrogen
St. Augustine
🌿 3 - 4 lbs of Nitrogen
Zoysia
🌿 2 - 3 lbs of Nitrogen
Centipede Grass
🌿 1 - 2 lbs of Nitrogen
The calculator adjusts fertilizer recommendations based on the selected grass type and fertilization schedule (spring, summer, fall, or winter).
Calculate Fertilizer Application for Grass
Different grass types have different nutrient needs. Our calculator considers your grass type and fertilizer type to determine the perfect fertilization schedule.
- Cool-season grasses (Kentucky Bluegrass, Fescue, Ryegrass) need fertilization in spring and fall.
- Warm-season grasses (Bermuda, Zoysia, St. Augustine) benefit from summer fertilization.
- Shade-tolerant grasses require less nitrogen to prevent overgrowth.
Determine Lawn Fertilizer Requirements
To determine how much fertilizer your lawn needs, follow these steps:
1️⃣ Measure your lawn: Enter the area in sq ft, m², or acres
2️⃣ Select your grass type: Choose from cool-season or warm-season grasses
3️⃣ Choose a fertilizer type: Urea (46-0-0), 10-10-10, Compost, etc.
4️⃣ Enter the nitrogen rate: Our calculator provides recommended values
5️⃣ Get your results: Find out how much fertilizer per 1,000 sq ft
How to Mix Fertilizer for Lawn (N-P-K Ratios)?
Mixing fertilizer properly ensures even nutrient distribution. Follow these steps:
Read the fertilizer label – Check the N-P-K ratio (e.g., 20-5-10 means 20% nitrogen, 5% phosphorus, 10% potassium).
Measure lawn size – Use the calculator to determine fertilizer application rate.
Apply evenly – Use a broadcast or drop spreader for solid fertilizers or a sprayer for liquid fertilizers.
Follow the recommended frequency – Fertilize 2-4 times a year depending on your grass type.
How Much Fertilizer Per 1,000 Square Feet?
The ideal amount depends on your grass type and fertilizer choice. Below are some common recommendations:
Urea
🧪 N-P-K: 46-0-0
📏 Application Rate: 1 lb of nitrogen = 2.2 lbs of fertilizer
10-10-10
🧪 N-P-K: 10-10-10
📏 Application Rate: 10 lbs of fertilizer per 1,000 sq ft
Compost
🧪 N-P-K: 1-1-1
📏 Application Rate: 100 lbs of fertilizer per 1,000 sq ft
Use our Lawn Fertilizer Calculator to get instant and accurate results for your lawn!
How to Mix DEF for Lawn Fertilizer Calculator?
For liquid fertilizer application, you need to mix water and fertilizer correctly to prevent over-fertilization.
- For granular fertilizer: Use 1 lb per 1,000 sq ft, spread evenly, and water after application.
- For liquid fertilizer: Use 1 gallon per 1,000 sq ft, ensuring uniform coverage.
- For slow-release fertilizers: Apply in spring and fall for sustained nutrition.
Frequently Asked Questions (FAQs)
1. How do I know how much fertilizer to apply?
Use our Lawn Fertilizer Calculator! Enter your lawn size, select your grass type, and choose the fertilizer type to get instant recommendations.
2. What is the best fertilizer ratio for lawns?
A balanced N-P-K ratio of 3-1-2 or 4-1-2 works best for most lawns, but it depends on the grass type and soil test results.
3. When should I fertilize my lawn?
✔ Spring – High nitrogen for growth
✔ Summer – Light feeding to avoid burning
✔ Fall – Balanced nutrients for root strength
✔ Winter – Slow-release fertilizer for dormant feeding
4. Can I use organic fertilizer instead of synthetic?
Yes! Organic options like compost, manure, and bone meal provide nutrients over time and improve soil health.
5. How do I avoid over-fertilizing my lawn?
Over-fertilization can burn grass and cause runoff pollution. Stick to recommended nitrogen rates based on grass type and avoid applying too frequently.
6. How do I calculate fertilizer per 1,000 square feet?
Use this simple formula:
Fertilizer Needed (lbs) = (Lawn Area × Recommended N Rate) ÷ Fertilizer N Content
7. Can I use liquid fertilizer instead of granular?
Yes! Convert granular to liquid using 1 gallon per 1,000 sq ft as a general guide.
8. Does fertilizer expire?
Granular fertilizers last years if stored dry, while liquid fertilizers may degrade over time.
Disclaimer for Lawn Fertilizer Calculator
This Lawn Fertilizer Calculator provides estimates based on standard recommendations. Actual fertilizer needs may vary due to soil conditions, climate, and specific grass variety. Always follow local guidelines and consult a lawn care professional before applying fertilizer. Use at your own discretion.
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