Percentage Calculator

To find a percentage of a number, convert the percentage to a decimal by dividing by 100, then multiply by the number. For example, 20% of 150 is 0.20 × 150 = 30. The calculator does this instantly: enter the percentage and the value, and it returns the result. This is the most common percentage operation, used for tips, discounts, commissions, and portions of a total.

Percentage change is the difference between two values divided by the original value, times 100. For an increase from 80 to 100, the change is (100 − 80) ÷ 80 × 100 = 25%. A negative result indicates a decrease. The calculator handles both directions automatically, which is useful for tracking price changes, growth rates, salary adjustments, and any comparison between an old and a new figure.

A percentage expresses a proportion of a value, while a percentage point is the arithmetic difference between two percentages. If an interest rate rises from 5% to 7%, that is an increase of 2 percentage points, but a 40% increase in relative terms. Confusing the two is a common source of misleading statements, so it helps to be clear which measure you mean when describing a change.

Divide the part by the whole and multiply by 100. For example, if 45 of 180 students passed, the pass rate is 45 ÷ 180 × 100 = 25%. The calculator performs this directly, which is handy for working out scores, completion rates, market shares, and any situation where you need to express one quantity as a proportion of another.

Yes. If you know the final amount after a percentage change, you can work backward to the original. For instance, if a price is 120 after a 20% increase, the original was 120 ÷ 1.20 = 100. This reverse calculation is essential for removing tax from a gross figure or finding a pre-discount price, and the percentage tools make it straightforward.