The basic bundle pricing formula is bundle price = sum of regular prices x (1 - discount). A three-item set worth $60 at 20% off sells for $48. The harder question is how deep that discount can go before the bundle earns less than the order it replaces. This post gives you the formulas for that, worked through with example numbers.
If you are still choosing which products to bundle, start with our product bundling strategy post. For bundle types and setup, see the product bundles guide.
What is the basic bundle pricing formula?
There are three ways to set a bundle price. Each one has a simple formula, and each one gives you a real discount you can compare.
| Pricing method | Bundle price | Real discount |
|---|---|---|
| Percentage off | Sum of regular prices x (1 - discount %) | The percentage you set |
| Amount off | Sum of regular prices - amount | Amount / sum of regular prices |
| Fixed bundle price | The price you choose | 1 - bundle price / sum of regular prices |
“Sum of regular prices” means what the items cost when bought one by one, at the price you normally charge.
For example, with made-up numbers, say a skincare set has a cleanser at $18, a toner at $16 and a moisturizer at $26. The sum is $60.
- 20% off gives a bundle price of $60 x 0.80 = $48.
- $10 off gives $50, a real discount of 10 / 60 = 16.7%.
- A fixed price of $47 gives a real discount of 1 - 47 / 60 = 21.7%.
Converting every offer to a real discount lets you compare a “Save $10” bundle with a “20% off” bundle on equal terms.
How do you work out the maximum bundle discount?
Price from profit, not from the discount you see elsewhere. The bundle has to earn at least as much as the order it replaces.
Start with the profit formula:
Bundle profit = bundle price - item costs - order costs
Item costs are what you pay for the products. Order costs are what you pay per shipment: packaging, pick and pack, and payment processing. Then set bundle profit equal to your baseline profit and solve for the discount:
Max discount = 1 - (item costs + order costs + baseline profit) / sum of regular prices
Baseline profit is the profit on the order the bundle most often replaces. For many stores, that is one unit of the best seller.
Back to the skincare set. Say the items cost you $5, $4 and $8, so item costs are $17. Most customers buy the moisturizer alone. That order earns $26 - $8 - $4 order costs = $14. The bundle ships in a bigger box, so its order costs are $5.
Max discount = 1 - (17 + 5 + 14) / 60 = 1 - 36 / 60 = 40%
At 40% off, the bundle earns the same $14 as a single moisturizer. That is your ceiling, not your target. At 20% off, the $48 bundle earns $48 - $17 - $5 = $26, almost double the baseline.
What about customers who already buy the full set?
The formula above assumes the bundle replaces a smaller order. Some customers already buy all three items at full price. For them, every dollar of discount is a dollar of lost profit.
A simple check: count how many recent orders already contain the full set. If it’s a large share, keep the discount small or offer a free gift instead. Then compare the result against your baseline after a few weeks.
What is the real discount on BOGO and buy X get Y?
Buy X get Y deals sound smaller than they are. When all items share one price, use this formula:
Real discount = (items you get x discount on them) / total items
| Offer | Formula | Real discount |
|---|---|---|
| Buy 1 get 1 free | 1 x 100% / 2 | 50% |
| Buy 1 get 1 at 50% off | 1 x 50% / 2 | 25% |
| Buy 2 get 1 free | 1 x 100% / 3 | 33.3% |
| Buy 2 get 3 free | 3 x 100% / 5 | 60% |
| Buy 3 get 6 free | 6 x 100% / 9 | 66.7% |
Run each of these through the max discount formula before you launch. A deal that looks generous on the product page can sit above your ceiling. The BOGO guide works through the margin table for “free” offers.
If the free item is a gift rather than more of the same product, your cost is the gift’s unit cost, not its retail price. A gift that sells for $15 but costs you $4 adds $4 to your order costs.
Which bundle pricing model fits your offer?
Pick the model that matches the bundle type and how often your prices change.
| Pricing model | How it works | Best for | Watch out for |
|---|---|---|---|
| Percentage off the sum | The discount follows item prices | Mix and match, build your own, sets with changing prices | Odd final prices, such as $47.20 |
| Amount off | “Save $10” on the set | Higher-priced sets, where dollars read better than percent | The real discount shrinks as prices rise |
| Fixed bundle price | One round price for the set | Gift sets, kits, holiday boxes | Recheck it when an item’s price or cost changes |
| Tiered discount | Bigger discount at higher quantities | Quantity breaks, bundle builders | Each tier needs its own profit check |
| Gift with purchase | Full price plus a free item | Keeping your regular price intact | Gift cost, and gift stock running out |
A pure bundle, sold only as a set, is a special case. With no separate prices to compare against, there is no “sum of regular prices”. Price it like any single product, and don’t claim a saving.
How do you price tiers in a tiered bundle?
Check the profit of every tier, then check what each step adds. The step from one tier to the next should still earn you something worthwhile.
Extra profit from a step = profit at the new tier - profit at the tier below
For example, with made-up numbers: a coffee bag sells for $16, costs you $6, and each order costs $3 to pack and ship.
| Tier | Price per bag | Order total | Profit per order | Extra profit from the step |
|---|---|---|---|---|
| 1 bag | $16.00 | $16.00 | $7.00 | n/a |
| 2 bags, 10% off | $14.40 | $28.80 | $13.80 | $6.80 |
| 3 bags, 15% off | $13.60 | $40.80 | $19.80 | $6.00 |
| 4 bags, 25% off | $12.00 | $48.00 | $21.00 | $1.20 |
| 4 bags, 20% off | $12.80 | $51.20 | $24.20 | $4.40 |
Every tier earns more than a single bag. But at 25% off, the fourth bag adds only $1.20 of profit. At 20% off, it adds $4.40. A smaller step at the top tier keeps the offer worth running.
For a per-item price, the formula is price per item = regular price x (1 - discount). At 15% off, that is $16 x 0.85 = $13.60. Our quantity breaks guide covers how to set and show these tiers on the product page.
How do discount codes change your bundle price?
Stacked discounts multiply. They don’t simply add up. Shopify applies product discounts first, and “all order discounts are applied on the order subtotal after product discounts have been applied” (Shopify Help Center).
Combined discount = 1 - (1 - first discount) x (1 - second discount)
A 15% bundle discount plus a 10% order code gives 1 - 0.85 x 0.90 = 23.5% off. Run that number through your max discount formula too.
Discounts only stack when you allow it. Shopify says multiple discounts apply “only when the setting on each discount allows the combination”. If they can’t combine, “the best discount for the customer’s cart is always applied”. So decide your stacking rules before a sitewide sale, not during it.
How should you round and display a bundle price?
Pick the price shoppers will see first, then work back to the discount. A round $48 reads better than $47.20, and the real discount formula tells you what it costs.
A few display habits:
- Show the saving in both forms. “Save $12 (20%)” lets shoppers compare quickly.
- Use a real reference price. The “before” price should be the sum of what you actually charge for each item.
- Keep steps clear. 10%, 15% and 20% are easier to compare than 9%, 13% and 17%.
- Recheck fixed prices. If you raise an item’s price, a fixed bundle price now gives a bigger discount than you planned.
Why does the reference price matter?
In the US, the FTC’s pricing guides say a former price is a fair basis for comparison when it is “the actual, bona fide price at which the article was offered to the public on a regular basis” for “a reasonably substantial period of time” (16 CFR 233.1). For offers tied to buying another item, such as BOGO, they warn against a seller who “increases his regular price of the article required to be bought” (16 CFR 233.4).
In plain terms: compare against prices you really charge, and don’t raise them for the sale. This is general information, not legal advice.
How does Sam Bundles apply your bundle price?
Sam Bundles is our bundle app for Shopify. Each offer type takes the pricing inputs below:
| Offer | Pricing inputs |
|---|---|
| Quantity breaks | Each bar priced at Full price, Percentage off, Amount off or Fixed price |
| Buy X, get Y | The Buy quantity and price, and the Get quantity, price type and discount per item |
| Fixed bundle | Percentage off or Amount off, or edit the Bundle price to set your own |
| Mix & Match | Percentage off or Amount off, with an option to use the product’s compare-at price |
| Bundle Builder | Percentage off or Amount off, set for tiers such as Buy at least 3 items |
A few details that matter for your formulas:
- Check the template defaults. The Buy X, get Y template starts with buy 1 get 1 free, buy 2 get 3 free and buy 3 get 6 free. That is 50%, 60% and 66.7% off. Edit the bars to match your ceiling.
- Use the preview. The buy X get Y Preview shows the price the customer pays and what they save. Compare it with your max discount.
- Compare-at prices. In Mix & Match, only tick Use the product’s compare-at price if those prices are ones you really charged.
- How the bundle price is split. For a fixed bundle, Sam Bundles splits the bundle price across the items in proportion to their regular prices. The $48 skincare set becomes $14.40, $12.80 and $20.80 on the order. That is useful when you refund one item.
Discounts apply automatically in the cart and at checkout. Under Advanced, you choose whether an offer combines with product, order or shipping discounts. The offer settings guide covers that card, and set up a fixed bundle walks through the pricing fields.
How do you know your bundle price is right?
Measure it against the baseline you used in the formula. After a few weeks, check:
- Profit per order on orders with the bundle, using your real costs.
- Average order value and units per order.
- Which tier people pick. If almost everyone takes the top tier, your discount may be deeper than it needs to be. If almost nobody does, the step may be too small.
- Full-set orders before and after. If they were common before, check how much discount you gave away on them.
The Sam Bundles dashboard shows additional revenue, AOV increase and add to cart rate, with results for each offer. Adjust one price at a time, so you can tell which change moved the numbers. For more on putting the offer live, see how to create bundles on Shopify.
Frequently asked questions
What is the formula for bundle pricing?
Bundle price = sum of the regular prices x (1 - discount). For an amount off, subtract the amount from the sum. If you set the bundle price yourself, the real discount is 1 - bundle price / sum of the regular prices.
How much discount should a bundle have?
There is no standard number. Work out the maximum discount where the bundle earns the same profit as the order it replaces, using max discount = 1 - (item costs + order costs + baseline profit) / sum of regular prices. Then pick a discount well below that ceiling and test it.
What is the real discount on buy 2 get 1 free?
One third, or about 33%, when the items have the same price. The formula is free items / total items. Buy one get one free is 50%, and buy 3 get 6 free is about 67%.
Should I use a percentage off or a fixed bundle price?
A percentage off follows your regular prices when they change, so it is easier to maintain. A fixed price lets you show a round number, such as $48, but you have to recheck it whenever an item price or cost changes.
How is a bundle price split when one item is refunded?
It depends on your app. In Sam Bundles, fixed bundle, mix and match and bundle builder orders list each product as its own line at its bundle price. A simple refund rule is to refund the price the customer paid for that line, not the full regular price.
Sources
Part of our guide: Product bundles →