Relate a percent, a whole, and an amount — solve for any one when two are known.
Formula
amount = (percent / 100) × whole
Explanation
A percentage is a ratio out of 100. Multiply the whole by percent÷100 to get the amount. Rearrange to find percent (amount÷whole×100) or the whole (amount÷(percent÷100)).
Variables
percentthe rate out of 100
wholethe reference quantity (100%)
amountthe portion that corresponds to the percent
When to use
Discounts, tips, tax, test scores, and any “what is X% of Y?” or “X is what percent of Y?” question.