About the Percent Off Calculator
A percent off calculator finds what you pay after a percentage reduction. It is the simplest and most frequently needed retail calculation, and worth being able to do quickly in a shop.
The formula
Final price = price · (1 − percent / 100)Percent off is subtracted from 100 to give the proportion you pay. 30 percent off means paying 70 percent of the original.
How to use this calculator
- 1Enter your Original Price ($). The field starts at
250, which you can overwrite. - 2Enter your Percent Off (%). The field starts at
30, which you can overwrite. - 3Read the result straight away — it recalculates as you type, so there is no button to press. Use Share to copy a link that reopens the page with your exact numbers filled in.
Worked example
| Input | Value |
|---|---|
| Original Price ($) | 250 |
| Percent Off (%) | 30 |
Result
Final Price: $175.00
Savings: $75.00
You Pay: $175.00 (70% of original)
Those are the values the page loads with, so you can reproduce this result yourself and then change one field at a time to see what drives the outcome.
Understanding your result
The mental shortcut is to calculate what you pay rather than what you save. For 30 percent off, find 70 percent directly — that is one step rather than two, and avoids the subtraction error. Ten percent is easy to find by moving the decimal, and most other percentages build from combinations of 10 percent, 5 percent, and 1 percent.
Sale pricing is designed to exploit the difficulty of quick comparison. Discounts are quoted from a reference price that may never have been charged, and multiple offers are structured so that the best deal is not obvious. Calculating the actual final price is the only reliable defence.
Things worth knowing
- Calculate what you pay, not what you save. It is one step instead of two.
- Ten percent of any number is that number with the decimal moved one place left.
- Half of 10 percent gives 5 percent, and combining gives 15, 20, 25 and so on.
- Sales tax is applied after the discount, so calculate the reduction first.
- A 33 percent discount is roughly one third off, which is often easier to compute mentally.
Frequently asked questions
How do I calculate 30 percent off?+
Multiply by 0.7 to get what you pay. A 250 dollar item at 30 percent off costs 250 × 0.7 = 175, saving 75.
What is the fastest way to do this mentally?+
Find 10 percent by moving the decimal one place, then scale. For 30 percent of 250: 10 percent is 25, so 30 percent is 75, leaving 175 to pay.
Is sales tax applied before or after the discount?+
After. Tax is calculated on the discounted price you actually pay, so the discount reduces the tax as well.
How do I compare two different offers?+
Calculate the final price for each rather than comparing percentages. Discounts applied to different starting prices are not directly comparable.