Percentage Calculator

Free percentage calculator: X% of Y, what percent X is of Y, percent change, and your grade percentage from points earned, with the working shown.

Free, no account and no AI. Every calculation runs in your browser and nothing you type is sent anywhere.

How it works

Pick the question you are asking: a percent of a number, what percent one number is of another, the percent change, or a grade from points.
Type the two numbers. The answer appears as you type, with the formula and the working underneath.
For a grade, enter the points you earned and the points possible to get the percentage and the letter grade.

The formulas

X% of Y: multiply Y by X and divide by 100. 15% of 80 = 80 x 15 / 100 = 12.
X is what percent of Y: divide X by Y and multiply by 100. 12 is 12 / 80 x 100 = 15% of 80.
Percent change from A to B: subtract A from B, divide by A, and multiply by 100. From 50 to 65 is (65 - 50) / 50 x 100 = 30% increase; from 80 to 60 is (60 - 80) / 80 x 100 = 25% decrease.
X is P% of what: divide X by P and multiply by 100. If 12 is 15% of a number, the number is 12 / 15 x 100 = 80.
Grade percentage: points earned divided by points possible, times 100. 43 out of 50 = 86%.

Percent change versus percentage points

When a percentage itself changes, say whether you mean percentage points or percent. A test average that rises from 70% to 77% has gone up 7 percentage points, which is a 10% increase on the old average (7 / 70 x 100). Both are correct; they answer different questions.

Percent changes also do not cancel out. A price that rises 20% and then falls 20% ends lower than it started: 100 becomes 120, and 120 minus 20% is 96.

Grade percentage and letter grade

To turn a score into a percentage, divide the points you earned by the points possible and multiply by 100. The letter grade here uses a common US scale: A+ 97 and above, A 93, A- 90, B+ 87, B 83, B- 80, C+ 77, C 73, C- 70, D+ 67, D 63, D- 60, and F below 60. Schools and instructors set their own cut-offs (some give an A from 90), so check your syllabus.

For a whole class rather than one assignment, use the grade calculator or the weighted grade calculator. The test grade calculator works from the number of questions you got wrong, the final grade calculator tells you the score you need on the final, and percentage to GPA converts a percentage to the 4.0 scale.

Everyday percentage questions

A discount: 25% off 60 dollars is 60 x 25 / 100 = 15 dollars off, so you pay 45. Or multiply by 0.75 directly.
A tip: 18% of a 42 dollar bill is 42 x 18 / 100 = 7.56 dollars.
A test score: 18 right out of 25 is 18 / 25 x 100 = 72%.
Growth: a class that grows from 24 to 30 students has grown (30 - 24) / 24 x 100 = 25%.

More free calculators

The GPA calculator, the what grade do I need calculator and the weighted average calculator also run in your browser. For writing, try the word counter. Everything is listed on the tools page.

Frequently asked questions

How do I calculate a percentage of a number?

Multiply the number by the percentage and divide by 100. For example, 15% of 80 is 80 x 15 / 100 = 12.

How do I work out what percent one number is of another?

Divide the part by the whole and multiply by 100. For example, 12 out of 80 is 12 / 80 x 100 = 15%.

How do I calculate percent change?

Subtract the old value from the new value, divide by the old value, and multiply by 100. A positive answer is an increase and a negative answer is a decrease. From 50 to 65 is a 30% increase.

How do I calculate my grade percentage?

Divide the points you earned by the points possible and multiply by 100. For example, 43 out of 50 is 86%, which is a B on the common US scale used here.

What letter grade is 86 percent?

On the common US scale used here, 86% is a B (83 to just under 87). Your school may use different cut-offs, so check your syllabus.

Is the percentage calculator free?

Yes. It is free with no account, and the numbers you type stay in your browser.

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