Reverse Percentage Calculator
Work backward from a final price to find the original amount, including through multiple stacked discounts or taxes applied one after another.
Enter each step in the order it was applied, most recent last. Use negative for a discount, positive for tax/markup.
All calculations run in your browser. Nothing is sent to a server.
Working backward from a discounted or taxed price to the original is a one-step calculation when only one percentage was applied, similar to the reverse mode already built into the Percentage Calculator. It gets more complicated when a price went through several changes in sequence, like a markup followed by a seasonal discount, or sales tax added on top of an already-discounted price. The multi-step mode below unwinds that whole sequence in the correct order, one change at a time.
Related Calculators
How It Works
If X% was added: Original = Final ÷ (1 + X/100)
A jacket on sale for $42 after a 30% discount: 42 ÷ (1 − 0.30) = $60 original price.
For a multi-step sequence, each step has to be unwound in reverse order, since the last change applied is the first one that needs to be removed to get back toward the original.
Where This Comes Up
Checking whether an advertised discount is calculated correctly, figuring out the pre-tax price of something when only the tax-inclusive total is shown, or reconstructing an original price after a product has gone through a markup and then a clearance discount are all situations where the final number is known but the starting point isn't.
Verifying Sale Claims
A "70% off" sticker is a claim, not a guarantee, and retailers occasionally inflate the reference price to make a discount look bigger than it actually is. Working backward from the sale price using the stated percentage and comparing that to the item's regular price elsewhere is a quick way to confirm whether the discount is real.
Expense and Invoice Reconciliation
An invoice or receipt that only shows a tax-inclusive total sometimes needs to be broken back down into the pre-tax amount for expense reporting or accounting purposes, particularly when tax needs to be recorded separately from the cost of goods or services. The Sales Tax Calculator handles this same extraction directly if tax is the only step involved.
Multi-Stage Pricing in Retail
A product's shelf price is often the result of several changes stacked on top of a base cost: a wholesale markup, then a promotional adjustment, then a final clearance discount. Reconstructing what that base cost was, whether for accounting, negotiation, or simple curiosity, requires unwinding each of those steps in the correct reverse order, which is exactly what the multi-step mode above is built to do.
Common Mistakes
Frequently Asked Questions
How do I find the original price before a discount?
Divide the final price by (1 minus the discount as a decimal). For a 30% discount, divide by 0.70, not by 1.30.
How do I find the pre-tax price from a tax-inclusive total?
Divide the total by (1 plus the tax rate as a decimal). For an 8% tax, divide by 1.08.
What if a price had a discount and then tax was added afterward?
Reverse the steps in the opposite order they happened. Since tax was added last, remove it first, then remove the discount from what's left. The "Multi-Step" mode above handles this automatically.
Can this be used to check if a "percent saved" claim on a sale is accurate?
Yes. Enter the sale price and the claimed discount percentage in the single-step mode, and compare the calculated original price against the price the item was actually listed at before the sale.
Does this work for percentage increases as well as discounts?
Yes. The "Was this a" selector in the single-step mode switches the formula between a subtracted discount and an added increase or tax, so both directions are handled by the same tool.