Lime Application Rate Calculator
Turn your soil test numbers into a lime plan you can take to the store. Enter your pH, lawn size, and product details — the calculator handles the rate, the schedule, and the bag count.
Soil test values
From your soil test report
6.5 is ideal for most lawns
Buffering data
Buffer pH gives the most accurate rate. If your report only shows current pH, use the texture estimate instead.
Also called SMP buffer pH or index pH
Lawn size & product
Exclude beds, walks, structures
Check the bag label. 90% is typical for pelletized lime.
Your lime plan
Application schedule
— pass(es)Single-pass cap: Applications are capped at 50 lbs per 1,000 sq ft per pass. Larger totals are split automatically. Wait 2–3 months between passes to let each dose work before adding more.
How this calculator works
When you provide a buffer pH, the calculator uses an interpolation of the SMP (Shoemaker-McLean-Pratt) buffer method — the same approach behind most university extension lime recommendations. Buffer pH measures how strongly your soil resists pH change, which is why two lawns with identical current pH can need very different amounts of lime.
When buffer pH isn't available, the calculator falls back to a texture-based estimate. Sandy soils change faster with less product; clay soils hold on tighter and need more. This estimate is useful for rough planning but less precise than the buffer method.
The CCE adjustment accounts for the neutralizing power of the actual product you buy. A bag with 80% CCE delivers less correction per pound than one at 100%, so you need more material. Most pelletized lime runs around 85–95% CCE.
For a deeper walkthrough of the inputs, the math, and how to pick the right product at the store, read the full lime application rate guide.