Lime Requirement Calculator
Converts a soil test lime recommendation into a rate of the product you can buy.
Share sends a link that reopens these numbers. Copy details pastes the full breakdown as a list.
The formula
product rate = recommended rate × assumed value ÷ your product’s value
A weaker product needs a proportionately larger dressing. CCE (calcium carbonate equivalent) sets pure calcium carbonate at 100, and NV sets calcium oxide at 100, so the two scales differ.
What to watch out for
The amount of lime needed depends on how far the pH has to move and on the soil’s buffering, which is much higher in clay and organic soils. That is why a lab measures it. Retest after a year or two rather than adding more on the strength of a single reading.
Frequently Asked Questions
How much product if the test says 2.5 t/ha at 100, and mine is 90?
2.78 t/ha.
Can I work out lime from pH alone?
Not reliably. Two soils at the same pH can need very different amounts, depending on their clay and organic matter. Get a recommendation from a soil test.