The short answer
Your deepest safe discount is your profit per unit divided by what you keep from the price after percentage fees. On an example $40 Amazon FBA product that earns $16.50, that ceiling is about 48%. But the ceiling only tells you where you stop making money. The more useful number is how many extra orders a discount needs: at 25% off, that same product has to sell just over twice as many units to earn the same profit as at full price.
Black Friday 2026 falls on Friday, November 27, and Cyber Monday on November 30. If you set your discounts before then with the numbers below, you'll know which offers pay for themselves and which only move units.
Why a discount hits profit harder than price
When you cut the price, only some of your costs fall with it. Percentage fees shrink, because they're charged on the lower price. Fixed costs don't. Your product cost, shipping, packaging and an Amazon FBA fulfillment fee stay exactly the same whether the item sells for $40 or $30.
- Falls with the price: Amazon's referral fee (a percentage of the total price, 8% to 15% in most categories), the percentage part of card processing, Etsy and eBay percentage fees.
- Stays the same: cost of goods, shipping, the per-unit FBA fee (tiered by size and weight, not price), the 30¢ part of a Shopify Payments charge.
So every dollar you take off the price comes almost entirely out of your profit. A 20% discount doesn't cut your profit by 20%. On the product below, it cuts it by 41%.
The three formulas you need
First work out what you keep from each dollar of price after percentage fees. With a 15% referral fee you keep 85 cents. Call the result your net price.
Net price = Price × (1 − percentage fees)
Maximum discount = Profit per unit ÷ Net price
Sales needed = Maximum discount ÷ (Maximum discount − Your discount)
The last line tells you how many times your normal unit sales you need at the sale price to earn the same total profit. A result of 1.5 means 50% more orders. These formulas are exact when your only price-linked costs are percentage fees, which is true for most marketplace sellers.
Worked example: a $40 Amazon FBA product
Assume a $40 product in a category with a 15% referral fee. Landed product cost is $10, the FBA fulfillment fee is $6.50 per unit (an assumed figure that includes Amazon's holiday peak fee and fuel surcharge; check your own in our FBA calculator), and storage and packaging add $1. Ads are left out for now.
At full price the referral fee is $6.00 and profit is $16.50, a 41% margin. Net price is $34.00, so the maximum discount is $16.50 ÷ $34.00, or about 48.5%. Below $20.59 you lose money on every unit.
| Discount | Price | Fee | Profit | Margin | Orders needed |
|---|---|---|---|---|---|
| None | $40.00 | $6.00 | $16.50 | 41.2% | 1.00× |
| 10% | $36.00 | $5.40 | $13.10 | 36.4% | 1.26× |
| 15% | $34.00 | $5.10 | $11.40 | 33.5% | 1.45× |
| 20% | $32.00 | $4.80 | $9.70 | 30.3% | 1.70× |
| 25% | $30.00 | $4.50 | $8.00 | 26.7% | 2.06× |
| 30% | $28.00 | $4.20 | $6.30 | 22.5% | 2.62× |
| 40% | $24.00 | $3.60 | $2.90 | 12.1% | 5.69× |
"Fee" is the referral fee, "Profit" is per unit, and "Orders needed" is a multiple of your normal unit sales. Look at the jump between rows. Going from 25% to 30% off adds only five points of discount, but you now need 2.62 times your normal orders instead of 2.06. At 40% off you need almost six times your usual volume to stand still. Few products see that kind of lift, even on Black Friday.
The same math on a Shopify store
Now a $50 product sold on Shopify Basic with Shopify Payments, which charges 2.9% + 30¢ per online card sale in the US. Product cost is $18 and shipping is $7. At full price, fees are $1.75 and profit is $23.25, a 46.5% margin.
| Discount | Price | Profit | Margin | Orders needed |
|---|---|---|---|---|
| None | $50.00 | $23.25 | 46.5% | 1.00× |
| 10% | $45.00 | $18.39 | 40.9% | 1.26× |
| 20% | $40.00 | $13.54 | 33.9% | 1.72× |
| 25% | $37.50 | $11.11 | 29.6% | 2.09× |
| 30% | $35.00 | $8.68 | 24.8% | 2.68× |
| 40% | $30.00 | $3.83 | 12.8% | 6.07× |
The starting margin is higher, but the pattern is almost identical. Card fees are small, so nearly the whole discount comes out of profit. The maximum discount here is about 47.9%, a sale price of $26.06.
Don't forget your ads
A discount also raises the return you need from ad spend. Break-even ROAS is the sale price divided by profit before ads. On the Amazon product it's 2.42 at full price and 3.75 at 25% off, about 55% higher. Ads that were profitable in October can quietly lose money during the sale. Recalculate your targets with the break-even ROAS calculator using the sale price, not the list price.
How to set a Black Friday discount that pays
- Work out each product's maximum discount first. Put the cost and sale price into the calculator below. If a product earns a thin margin at full price, it can't carry a deep discount.
- Be honest about the lift. Ask what your sales did during last year's sale, or during your last promotion. If 20% off doubled orders, it paid. If it brought 30% more orders, it didn't.
- Discount your high-margin products. A 25% offer on a 60% margin item costs far less than on a 30% margin item. Lead with the products that can afford it.
- Try offers that protect margin. A dollar amount off an order above a threshold, a free gift with a low unit cost, or a bundle discount raises order value instead of just cutting price.
- Plan stock for the volume you need. If your offer needs twice your normal orders, you need the stock to fill them. Our reorder point calculator helps you plan for the spike.
- Watch fee thresholds. Some fees change at set prices. On Walmart, for example, a discount can drop an apparel item into a lower referral fee tier, as explained in our Walmart apparel price post.
Amazon's holiday fees in 2026
Amazon's holiday peak fulfillment fees apply to units that ship between October 15, 2026 and January 14, 2027, adding about $0.32 per unit on average in the US. A 3.5% fuel and logistics surcharge that started in April 2026 applies on top. Both are fixed costs per unit, so they make deep discounts slightly more expensive. Include them in your cost before you work out your maximum discount.
Frequently asked questions
When is Black Friday 2026?
Black Friday 2026 is Friday, November 27, the day after Thanksgiving on November 26. Cyber Monday is November 30, 2026.
How do I work out the maximum discount I can offer?
Divide your profit per unit by your price after percentage fees, such as a 15% referral fee. On a $40 product earning $16.50 with a 15% fee, that is $16.50 ÷ $34.00, or about 48.5%.
How many more sales does a 20% discount need?
It depends on your margin. On a product with a 41% margin after a 15% marketplace fee, 20% off needs about 1.7 times your normal orders to earn the same total profit.
Does Amazon's referral fee go down when I discount?
Yes. Amazon charges the referral fee as a percentage of the total sales price, so a lower price means a lower fee. The FBA fulfillment fee is based on size and weight, so it does not fall.
Do Amazon's holiday peak fees affect my Black Friday margins?
Yes. Amazon's 2026 peak fulfillment fees apply from October 15, 2026 to January 14, 2027 and average about $0.32 per unit in the US, plus a 3.5% fuel and logistics surcharge.
Sources
- Amazon: Selling on Amazon fees (referral fee basis and ranges)
- Amazon: FBA fees guide (per-unit fees tiered by size and weight)
- Shopify: Pricing (Shopify Payments online card rates)
- Walmart Marketplace: Referral fees
- Supply Chain Dive: Amazon announces 2026 holiday fulfillment fees
- ShopBack: Black Friday (Nov 27) vs Cyber Monday (Nov 30) 2026
Fees and policies change. Figures were checked against the sources above on November 12, 2026; always confirm your own rate in your seller account.