# Add or Subtract a Percentage

### Add or Subtract a Percentage Calculator

Start Value Percent End Value
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Details

## How to add a percentage to a number - Step by Step

To add a percentage (%) to a number, i.e., If you want to add a B percent to an A amount, you can use the following formula:

End Value = A + (B100 × A )

Where: A represents the start or inicial value and B the percent we want to add. See the example below:

### How to increase or add 10% to 100?

Plugging the values in the formula above:

End Value = 100 + (10 100 × 100)

End Value = 100 + (0.1 × 100)

End Value = 100 + (10)

## How to subtract a percentage from a number - Step by Step

To subtract a percentage (%) from a number, i.e., If you want to subtract a B percent from an A amount, you can use the following formula:

End Value = A - (B100 × A )

Where: A represents the start or inicial value and B the percent we want to subtract. See the example below:

### How to decreasee or subtract 10% to 100?

Plugging the values in the formula above:

End Value = 100 - (10100 × 100 )

End Value = 100 - (0.1 × 100)

End Value = 100 - (10)