CCE

Calcium Carbonate Equivalent (CCE) 

Calcium carbonate equivalent is a measure of how well a liming material can neutralize soil acidity. Pure calcium carbonate is used as the benchmark because it’s the main component of high‑quality agricultural limestone.

In the lab, CCE is determined by reacting to a known amount of the material being tested with hydrochloric acid and comparing it to the reaction of pure calcium carbonate under the same conditions. After the reaction, the remaining acidity is measured through titration. The CCE is calculated by comparing how much acidity the test material neutralizes relative to pure calcium carbonate, and the result is expressed as a percentage.

What This Means In Your Field 

CCE helps determine how much lime is needed to raise or maintain soil pH for a specific crop. Most agronomic recommendations assume a lime CCE of 90%, but real quarry‑sourced lime can range anywhere from 75% to 110%. That difference can change the required application rate by 20–30%, either up or down.

CCE from a single quarry tends to stay fairly consistent over time, but CCE can vary significantly between different quarries. While CCE is an important indicator of lime quality, it’s only one piece of the puzzle—other factors like particle size, purity, and moisture content also influence how effectively a lime source performs in the field.

IdaLIME has a CCE of 102. See how that compares to other options available.