A discount cuts your Amazon FBA profit by a bigger percentage than your price, because only the referral fee shrinks with it; the FBA fee stays put unless the price crosses a fee band. On a $24.99 pet product with a 15% referral fee, $7.00 landed cost and $4.76 FBA fee (2026 non-peak), 20% off cuts profit from $9.48 to $5.23 a unit, 45% less, so you need 1.81 times the units to make the same money. In the Oct 15, 2026 to Jan 14, 2027 holiday peak ($5.06 FBA fee), the same 20% off takes profit from $9.18 to $4.93, so you need 1.86 times the units.
Example product: pet products category, 14 oz in an 8 x 6 x 2.5 in box. FBA fee is $4.60 + 3.5% surcharge non-peak, $4.89 + surcharge in peak. Discount treated as a straight price cut; ads, storage and coupon fees not included.
What moves when you cut the price
- Price: drops by the full discount. 20% off $24.99 is $5.00 less per sale.
- Referral fee: 15% of the sale price, so that $5.00 cut saves only $0.75.
- FBA fulfillment fee: set by size tier, weight and price band. Inside a band it doesn't move, and the 3.5% surcharge is on the fee, not your price.
- Landed cost: the $7.00 for product, freight, duty and shipping to Amazon is already spent.
So in a 15% referral category, 85 cents of every discount dollar comes out of profit: $0.21 a unit per 1% off a $24.99 item.
Profit per unit at 10%, 20% and 30% off
Example product, 2026 non-peak rates (FBA fee $4.76 in every row). Units to match = full-price profit ÷ discounted profit.
| Discount | Price | Profit per unit | Profit lost | Units to match |
|---|---|---|---|---|
| None | $24.99 | $9.48 | 0% | 1.00x |
| 10% off | $22.49 | $7.36 | 22.4% | 1.29x |
| 20% off | $19.99 | $5.23 | 44.8% | 1.81x |
| 30% off | $17.49 | $3.11 | 67.2% | 3.05x |
The last column is the bar the promotion has to clear. At 20% off you need 81% more units to tie: 100 units a week at $24.99 makes $948, and matching that at $19.99 takes 182 units.
In the holiday peak, it gets a little worse
From October 15, 2026 to January 14, 2027, this item's FBA fee rises $0.30 to $5.06 ($4.89 + $0.17 surcharge):
| Discount | Price | Profit per unit | Profit lost | Units to match |
|---|---|---|---|---|
| None | $24.99 | $9.18 | 0% | 1.00x |
| 10% off | $22.49 | $7.06 | 23.1% | 1.30x |
| 20% off | $19.99 | $4.93 | 46.3% | 1.86x |
| 30% off | $17.49 | $2.81 | 69.4% | 3.27x |
Worked example: 20% off a $24.99 item
- New price: $24.99 x 0.80 = $19.99.
- Referral fee: 15% x $19.99 = $3.00, down from $3.75.
- Size tier: thicker than 0.75 in, so large standard. Dimensional weight (8 x 6 x 2.5 ÷ 139) is 0.86 lb, under the 14 oz unit weight, so Amazon bills 14 oz.
- FBA fee: $19.99 is still in the $10 to $50 band: $4.60 + $0.16 surcharge = $4.76, same as at full price.
- Landed cost: $7.00, unchanged.
- Profit: $19.99 − $3.00 − $4.76 − $7.00 = $5.23, down from $9.48.
- Cost of the discount: $5.00 price cut − $0.75 lower referral fee = $4.25 a unit, 44.8% of your profit.
- Units to match: $9.48 ÷ $5.23 = 1.81.
When a price cut crosses a fee band
The 2026 FBA fee has three price bands: under $10, $10 to $50 (both ends included) and over $50. Cut your list price into a lower band and the fee drops too. Same box, non-peak. Profit lost doesn't depend on landed cost, so the last column holds for any 15% referral item this size and weight:
| Price change | FBA fee | Price cut | Profit lost per unit |
|---|---|---|---|
| $53.99 → $48.59 (10% off) | $5.03 → $4.76 | $5.40 | $4.32 |
| $11.99 → $9.59 (20% off) | $4.76 → $3.91 | $2.40 | $1.19 |
Inside one band, fees absorb only 15% of a price cut. From $11.99 to $9.59, the lower FBA and referral fees absorb about half. The edges matter at full price too: for this box, any price from $10.00 to $10.98 keeps less per unit than $9.99, and $50.01 to $50.31 keeps less than $50.00, whatever your landed cost. If you sit just above $10 or $50, try the edge price before a coupon.
For a coupon or deal, check a settlement report to see whether the fee band followed the post-coupon price before you count on the lower fee.
Coupons and deals cost extra
Amazon charges a separate fee to run a coupon or a deal. It isn't in my calculator's fee data, so check the current fee in Seller Central, divide it by the units you expect to sell on the promotion, and subtract that from profit per unit. Every multiple above goes up. After your first coupon orders, check the settlement report for what Amazon actually charged.
My rules of thumb before I discount
- Work out the units multiple first. If I don't believe the promotion will bring that many extra sales, I don't run it.
- Know your break-even discount: profit margin ÷ 0.85 in a 15% referral category, if the discounted price stays in the same FBA price band. This item makes 37.9% non-peak, so profit hits zero at 44.6% off, about $13.84. If the price would cross $10 or $50, use the calculator instead.
- Count your ads. With an example $2.00 of ad spend per unit, 20% off needs 2.32 times the units non-peak, not 1.81.
- Have a reason, like a launch push for sales rank, and budget it like ad spend: 20% off on 500 units of this item gives up $2,125.
- Don't discount a small item to dodge storage. October to December storage for this box is $0.17 a unit per month; 20% off costs $4.25, about 25 times more. Bulky items, or stock facing an aged-inventory surcharge (check Seller Central for the amount), can be different.
Fee data: these rates match the calculator's 2026 data (US, non-apparel), checked against Seller Central on September 26, 2026. The example product and its $7.00 landed cost are made up for illustration. Amazon changes fees, so always confirm in Seller Central before pricing.
FAQ
Should I run a 20% coupon on Amazon?
Only if you expect enough extra sales. In my $24.99 example with a $7.00 landed cost, 20% off cuts profit from $9.48 to $5.23 a unit at 2026 non-peak fees, so you need 1.81 times the units (1.86 in the Oct 15, 2026 to Jan 14, 2027 peak). That treats the coupon as a straight price cut before Amazon's coupon fee; check your settlement report for what was actually charged.
How many more units do I need to sell after a discount?
Divide full-price profit per unit by discounted profit per unit. In my $24.99 example with 2026 non-peak FBA fees, 10% off needs 1.29 times the units, 20% off 1.81 times and 30% off 3.05 times. In the Oct 15, 2026 to Jan 14, 2027 holiday peak it is 1.30, 1.86 and 3.27 times.
Does a lower price reduce my Amazon FBA fees?
The referral fee drops, because it is a percentage of price. The FBA fulfillment fee only drops if the price crosses a band (under $10, $10 to $50, over $50). For a 14 oz item in an 8 x 6 x 2.5 in box, a list-price cut from $11.99 to $9.59 lowers the 2026 non-peak fee from $4.76 to $3.91. For a coupon, check your settlement report to see which band Amazon used.
How much does Amazon charge to run a coupon?
Amazon charges a separate fee for coupons and deals; it changes, so check the current amount in Seller Central. Spread it over the units you expect to sell on the promotion and subtract it from profit per unit.
See What Your Discount Really Costs
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