Percent Compass

PERCENTAGES, WITH A CLEAR DIRECTION

Percentage calculator

Add a percentage, take one off, or find the original value. Choose a calculation and enter your numbers.

Increase a value

Add a percentage of the starting value.

Use 0 or positive numbers, without commas or symbols.

Value after increase

100

Amount added 20

Updates as you type

How it’s calculated

New value = starting value × (1 + percentage ÷ 100)

80 × (1 + 25 ÷ 100)
= 100

Displayed results are rounded to at most 6 decimal places; very small or large numbers use scientific notation with up to 7 significant digits. Calculations use floating-point arithmetic, so results are approximate.

A QUICK GUIDE

Start with what you know.

Four ways to apply a percentage.
Each example is ready to try.

01 / Increase

What is the value after an increase?

The starting value is the base, or 100%. Add the requested percentage of that base.

A value of 80 increased by 25% is 100.

80 × (1 + 25 ÷ 100) = 100

Try this example
02 / Decrease

What remains after a decrease?

The decrease is measured against the starting value, not the value that remains.

A value of 200 decreased by 15% is 170.

200 × (1 − 15 ÷ 100) = 170

Try this example
03 / Discount

How much will I pay on sale?

The discount is a percentage of the original price. Savings equal the original price minus the sale price.

A $120 item at 20% off costs $96. You save $24 before taxes and fees.

$120 × (1 − 20 ÷ 100) = $96

Try this example
04 / Reverse

What was the value before the change?

Know the final value and the percentage? Divide to find the original. Choose whether the value increased or decreased. A 100% decrease cannot be reversed.

After a 20% discount, a price is $80. The original price was $100—not $96.

80 ÷ (1 − 20 ÷ 100) = 100

Try this example