Calculators guide
How to Calculate Percent Savings (and Why 30% + 20% Isn't 50%)
The percent savings formula with real examples, plus stacked discounts, dollar vs percent coupons, buy-one-get-one deals, bulk packs and annual plans.
By M2Toolkit Editorial TeamPublished 6 min read
Quick answer
Percent savings = (original price − price you paid) ÷ original price × 100.
A jacket marked down from $80 to $56 saves you $24. $24 ÷ $80 = 0.30, so you saved 30%. Always divide by the original price — dividing by the sale price gives 42.9%, which is the markup going the other way, not your saving.
The formula takes ten seconds. The hard part is the deals that are built to be confusing: two discounts stacked on top of each other, “buy two, get one free”, a dollar coupon versus a percent coupon, or a bulk pack that may or may not be cheaper per item. Each one is covered below with real numbers, so you can tell what a deal is actually worth before you pay.
The basic calculation, step by step
- 1Subtract what you paid from the original price. That's your saving in money.
- 2Divide the saving by the original price.
- 3Multiply by 100 to turn it into a percentage.
In a spreadsheet, with the original price in B2 and the price you paid in C2, the formula is =(B2-C2)/B2. Format the cell as a percentage and you're done.
Going the other way is just as useful. If you know the discount and want the final price, multiply by what's left:
25% off $64 is $64 × 0.75 = $48.
The most common mistake: dividing by the wrong number
Percentages always need a starting point. For savings, the starting point is the price before the discount. Here's what happens with the $80 → $56 jacket if you mix them up:
| Calculation | Result | What it means |
|---|---|---|
| $24 ÷ $80 | 30% | How much you saved. This is the one you want. |
| $24 ÷ $56 | 42.9% | How much more the full price is than the sale price. |
Both numbers are correct; they answer different questions. Retailers describing a markdown and shoppers describing a saving should both use the first.
Stacked discounts don't add up
“30% off, plus an extra 20% at checkout” sounds like 50% off. It isn't. The second discount is taken from the price that's already been reduced:
- 1$100 with 30% off is $70.
- 2An extra 20% off $70 is $14, leaving $56.
- 3You paid $56 for a $100 item: a total saving of 44%, not 50%.
| Advertised | Sounds like | Actually |
|---|---|---|
| 25% + extra 10% | 35% | 32.5% |
| 30% + extra 20% | 50% | 44% |
| 40% + extra 10% + extra 5% | 55% | 48.7% |
| 50% + extra 50% | 100% (free) | 75% |
The order of the two percentages doesn't matter: 20% then 30% gives the same 44% as 30% then 20%.
Try the free Discount CalculatorEnter the original price and both discounts to see the sale price, the money saved and the true total percentage.Percent-off coupon or dollar-off coupon?
When you can only use one — say $10 off or 15% off — there's a break-even price where they're worth exactly the same:
$10 ÷ 0.15 = $66.67. Below that, the $10 coupon saves more. Above it, the 15% coupon wins. On a $50 basket, $10 off is a 20% saving; on a $120 basket, 15% off is $18.
When you get to use both a percentage and a fixed amount, the order matters — unlike two percentages. Take $100 with 20% off and a $10 coupon:
| Order applied | Calculation | You pay |
|---|---|---|
| Percentage first | $100 × 0.8 − $10 | $70 |
| Coupon first | ($100 − $10) × 0.8 | $72 |
You don't usually get to choose — the checkout decides — but it explains why the total sometimes doesn't match what you worked out in the aisle.
Multi-buy offers as a percentage
For items that cost the same, multi-buy deals convert to a simple percentage off everything you take home:
| Offer | You pay for | Saving on the lot |
|---|---|---|
| Buy one, get one free | 1 of 2 | 50% |
| Buy two, get one free (3 for 2) | 2 of 3 | 33.3% |
| Buy three, get one free | 3 of 4 | 25% |
| Second one half price | 1.5 of 2 | 25% |
These only count as savings if you were going to buy the extra item anyway. “3 for 2” on something you only needed one of means paying twice what you came in to spend, with a free item attached.
Bulk packs: compare the price per item
A bigger pack is not always cheaper per unit, and the shelf label doesn't always make it easy to tell. Divide the price by the quantity for each option, then use the savings formula on the unit prices:
| Option | Price | Per can |
|---|---|---|
| 6-pack | $3.49 | $0.582 |
| 24-pack | $12.48 | $0.520 |
($0.582 − $0.520) ÷ $0.582 = 10.6%. The 24-pack saves about 11% per can — worth it if you'll drink 24 cans before they go out of date, not if half end up at the back of the cupboard. The Unit Price Calculator compares two products side by side, even when one is sold in grams and the other in kilograms.
Annual vs monthly plans
Subscription “save X% with annual billing” claims are worth checking the same way. A plan that costs $15.99 a month is $191.88 over a year. If the annual price is $159.99, the saving is $31.89:
That's a real saving — provided you'd keep the service all twelve months. If there's a fair chance you'll cancel after eight, the monthly plan costs $127.92 and the “saving” turns into a $32 loss. The Subscription Cost Calculator adds up everything you pay for across a year.
Where sales tax fits in
In most of the US, sales tax is charged on the price after a store's own discount, so tax shrinks along with the price. Manufacturer coupons are a different story in many states — tax can be charged on the pre-coupon price. Rules vary by state, so for an exact figure check your receipt. For countries with VAT, prices on the shelf already include it, and a percentage discount comes off the VAT-inclusive price. To add or strip VAT from a figure, use the VAT Calculator.
Frequently asked questions
How do I calculate percent savings?
Subtract the price you paid from the original price, divide the result by the original price, and multiply by 100. From $80 down to $56 is a $24 saving, and $24 ÷ $80 × 100 = 30%.
Is 30% off plus an extra 20% off the same as 50% off?
No. The extra 20% comes off the already-reduced price, so the total saving is 44%. A $100 item ends up at $56, not $50.
How do I find the original price from the sale price?
Divide the sale price by (1 − the discount as a decimal). A $45 item at 25% off was originally $45 ÷ 0.75 = $60.
What's the difference between percent off and percent savings?
Usually nothing — both compare the saving with the original price. They differ only when there are several discounts, in which case percent savings is the true combined figure and the advertised percentages are the individual steps.
Is buy one get one free 50% off?
For two items at the same price, yes: you pay for one and get two, a 50% saving on the pair. If you only wanted one item, you haven't saved anything — you've paid full price and received an extra.