About this tool
Lawn Lime & Soil pH Calculator is a free, in-browser tool that estimates how much lime or sulfur a lawn or garden bed needs to reach a target soil pH. Enter your current and target pH, pick the soil texture and the area, and it returns the pounds of material, the rate per 1,000 ft², and whether to apply lime or sulfur. Nothing is uploaded — the math runs on your device.
When the target is higher than the current pH, the tool applies lime and uses a texture-based rate to raise pH by 0.5: about 20 lb per 1,000 ft² for sandy soil, 40 for loam and 60 for clay. When the target is lower, it switches to elemental sulfur to lower pH by 0.5: about 10 lb for sandy, 15 for loam and 20 for clay. The amount scales linearly: pounds = rate × (pH change ÷ 0.5) × (area ÷ 1,000). Clay resists pH change most, so it needs the most material.
Use it as a planning estimate, not a lab prescription. Always start from a real soil test, split large applications into stages a few months apart, and re-test before adding more, because pH shifts slowly.