How much lime per acre of lawn?

First you need to determine if your lawn needs lime. Lime will increase the alkalinity of the soil. You want a fairly neutral soil for lawns. That is not too acidic or too alkaline. You need to determine the pH of your soil to learn the amount of lime that will provide the desired result. A soil test with recommendations specific to correcting pH can be obtained from your local county extension service. If your question has more to do conversions there are 43,560 square foot per acre.