Reverse Percentage Calculator

This calculator helps you find the original value before a percentage increase or discount was applied.

It is commonly used in retail pricing, VAT calculations, financial analysis, and business decision-making.

Reverse percentage calculations are essential when you only know the final value and need to work backwards.

This is one of the most important percentage calculations for understanding true costs and pricing.

Find original value

Understanding your result

The result shows the original value before the percentage change was applied.

This is calculated by reversing the percentage effect using division.

This ensures accuracy, as percentages are relative changes.

How the calculation works

Discount: Final ÷ (1 − percentage)

Increase: Final ÷ (1 + percentage)

This reverses the percentage effect instead of simply subtracting it.

Why reverse percentage is different

Many people incorrectly try to subtract percentages to find original values.

However, because percentages are relative, the correct method is division.

This is especially important in pricing and VAT calculations.

Examples

Example 1 (Discount):
£80 after 20% discount → £100 original

Example 2 (Increase):
£132 after 10% increase → £120 original

Example 3 (Retail):
£60 sale price after 25% discount → £80 original

Example 4 (VAT):
£120 including 20% VAT → £100 original price

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Frequently asked questions

What is reverse percentage?

It finds the original value before a percentage change.

How do I reverse a discount?

Divide by (1 − percentage).

Why not subtract?

Because percentages are relative, not absolute.