Percentage Calculator

Three percentage questions everyone runs into — discounts, grades, raises, growth — answered in one place.

1. What is X% of Y?

Percent (%)

Of value

2. X is what percent of Y?

Value

Of total

3. Percentage increase / decrease

Old value

New value

What is this tool?

Percentages show up everywhere in American life: a 30 percent-off sale, a sales tax rate, a test score, a 4 percent raise, a stock that moved 2.3 percent today. This percentage calculator handles the three calculations people actually need: finding a percentage of a number, working out what percentage one number is of another, and measuring the percent increase or decrease between an old and a new value.

Percent change is the one that trips people up most, because the base matters. A price that drops from $100 to $80 fell 20 percent, but climbing back from $80 to $100 is a 25 percent increase. Run the numbers here instead of guessing, whether you are checking a discount at the register, a tip, a grade, or year-over-year business growth.

How to use it

Choose the mode that matches your question — all three are on this page.
Enter the two values for that mode.
Click that mode's Calculate button and read the result instantly.

Formula & method

X percent of Y = (X ÷ 100) × Y. Share: X is what percent of Y = (X ÷ Y) × 100. Percent change = ((new − old) ÷ |old|) × 100; a positive result is an increase and a negative result is a decrease.

Worked example

A jacket marked down 30 percent from $120: 30 percent of $120 is $36, so you pay $84. A score of 45 out of 60 is 75 percent. And a salary rising from $50,000 to $54,000 is an 8 percent increase.

Frequently asked questions

How do I calculate a discount quickly?

Multiply the price by the discount percentage to find the savings, then subtract. Or multiply the price by (100 − discount) ÷ 100 to get the sale price in one step — 30 percent off $120 is $120 × 0.70 = $84.

What is the difference between percent and percentage points?

If an interest rate rises from 4 percent to 5 percent, that is a 1 percentage point increase but a 25 percent relative increase. News reports often blur the two, so check which one is meant.

How do I figure out a grade percentage?

Divide the points you earned by the total points possible and multiply by 100. For example, 45 out of 60 equals 75 percent, which is a C in most US grading scales.