Lime calculator
Sour soil locks up the fertiliser you already paid for. This works out how much pulverised limestone it takes to move your pH, and whether that is one pass or several.
Limestone needed
That is more than the 50 lb per 1,000 ft² most guides put on in one pass, so it is split into 2. Space them out — a season apart is common — and re-test before the last one.
Why soil texture changes the answer
Sand barely resists a change in pH; clay resists it hard. That resistance is called buffering, and it is why the same pH gap needs roughly three times as much limestone on clay as on sand. The rates here are the ballpark figures published by university turf extension services, per full point of pH.
A soil test beats this calculator. If you have a laboratory recommendation, follow it — it is measured from your actual soil rather than estimated from its texture. Use this to plan and to sanity-check, not to overrule a test.