On what?
Lawn (type of grass?), garden (vegetables, flowers, or...), trees (type), ...

Some soils need more than others. Depends on the local PH.
You'd have best success asking your question of someone local in your area, who is in the business, such as at a plant nursery.

50 pounds per 1000 SQFT to reduce acid levels by one. Mind block, cant remember if raising PH is alkaline or acid, either way Lime reduces the acid level, so its 50 pounds per 1000 sqft to reduce acid one level. You also need to get a good type of lime, one that is finely crushed and disperses quickly, and not farm field lime that is spread in the corn fields, it takes too long for any results.