bestquantity
nounUK /ˌbestˈkwɒntɪti/
US /ˌbestˈkwɑːntəti/
The best amount of something is just the right amount to use.
The best quantity of water for the plant is one small cup each day.
OTHER MEANINGS
2. The largest amount that is still good or useful.
For the recipe, the best quantity of sugar is two spoons, not more.
3. The amount that gives the best result.
Scientists found the best quantity of sunlight for the seeds to grow.
4. The most helpful number of items to have.
The best quantity of pencils for the class is one for each child.