Reverse Percentage Calculator
You have the result. Work backwards to find the original number before any percentage was applied.
How It Works
Most percentage calculators go forward: apply a percentage to a number and get a result. This one goes backwards. You have the result already, and you need to find out what the original number was before that percentage was applied.
There are two scenarios. First, a percentage was removed (a discount, reduction, or cut). Second, a percentage was added (a markup, tax, or increase). The formula is different for each:
Original = Final Value / (1 – Percentage / 100)
If a % was added:
Original = Final Value / (1 + Percentage / 100)
Example (added): Price $110 including 10% tax = 110 / (1 + 0.10) = 110 / 1.10 = $100 pre-tax
Select the right scenario above, enter the two numbers you know, and the original value appears instantly.
When People Actually Search This
Finding the original price before a discount
You see a product on sale for $240 and the tag says “20% off.” What was the original price? $240 / 0.80 = $300. You might want this to check whether the original price was inflated before the sale, or to compare across different stores with different discount percentages.
Finding the price before VAT or sales tax
A receipt shows $118 including 18% VAT. What was the pre-tax price? $118 / 1.18 = $100. This is a common business accounting question where you need to separate the tax portion from the base price. Finance teams run this calculation regularly.
Working out the original salary before a raise
Someone tells you their new salary is $56,000 after a 12% raise. What were they earning before? $56,000 / 1.12 = $50,000. This comes up in HR conversations, salary benchmarking, and personal finance planning.
Reversing a commission or markup
A real estate agent sold a property for $459,000 after adding a 2% commission to the seller’s net price. What was the seller’s net? $459,000 / 1.02 = $450,000. Buyers, sellers, and agents all need to run this calculation at different stages of a deal.
Recovering a value after a budget cut
A department’s budget was reduced by 15% to $425,000. What was the original budget? $425,000 / 0.85 = $500,000. Budget discussions always involve working backwards from the reduced figure to understand the original allocation.
Table of Truth: Common Reverse Percentage Results
Use this table to sanity-check your result or get a quick estimate.
| Final Value | % Applied | Scenario | Original |
|---|---|---|---|
| 80 | 20% off | Removed | 100.00 |
| 150 | 25% off | Removed | 200.00 |
| 240 | 20% off | Removed | 300.00 |
| 425,000 | 15% cut | Removed | 500,000.00 |
| 110 | 10% tax | Added | 100.00 |
| 118 | 18% VAT | Added | 100.00 |
| 56,000 | 12% raise | Added | 50,000.00 |
| 459,000 | 2% commission | Added | 450,000.00 |
| 85 | 15% off | Removed | 100.00 |
| 230 | 15% tax | Added | 200.00 |
Common Mistakes People Make
Real-Life Examples
Checking a sale price claim
A store says a jacket is 30% off and priced at $175. To check: $175 / 0.70 = $250 original price. You can now verify whether the original price was genuine by checking the same item elsewhere. If other stores sell it for $200, the “original” price may have been inflated before the sale.
Business calculating pre-tax revenue
A company invoices clients at a price that includes 7.5% sales tax. The invoice total is $10,750. What is the pre-tax revenue? $10,750 / 1.075 = $10,000. The company records $10,000 as revenue and $750 as tax collected. The reverse percentage formula separates those two numbers cleanly.
Employee verifying a salary after pay cut
An employee’s salary was reduced by 8% and is now $55,200. What was the original salary? $55,200 / 0.92 = $60,000. The employee can now confirm the reduction was applied correctly and that the math matches the HR communication.
