Find how many extra units a trade promotion must sell to pay for itself.
Enter your list price, cost, retailer margin and shelf discount. You get what you earn per unit on promotion, and how many units the promotion must sell to earn what you normally earn.
Your four numbers
To break even, the promotion has to sell 186 units for every 100 you normally sell.
That is 86% more units than usual, to earn the same dollars of margin.
- Shelf price
- $4.62 now, $3.92 on promotion
- You receive per unit
- $3.00 now, $2.31 on promotion
- Your margin per unit
- $1.50 now, $0.81 on promotion
- What the discount costs you
- $0.69 a unit, 23% of your list price
- Discount that wipes out your margin
- 32.5% off the shelf price
The calculator assumes the retailer keeps the same dollars per unit as today. If it earned a dollar a unit before the promotion, it still earns a dollar, so you pay the whole discount. The number covers the promotion period only. Fees you pay for the promotion, and the dip in sales after it ends, are not in it. Both raise the number of extra units you need.
The arithmetic behind the number
Every figure comes from the four numbers you enter, in these steps:
- Shelf price is your list price divided by one minus the retailer’s margin.
- Discount per unit is the shelf price times the shelf discount. You pay all of it.
- Your margin per unit on promotion is your list price minus the discount per unit minus your cost.
- Units the promotion must sell, for every 100 you normally sell, is 100 times your margin today (list price minus cost) divided by your margin on promotion.
The discount that wipes out your margin per unit is your margin per unit today divided by the shelf price.
Have an AI assistant run the whole promotion sheet.
Week 1 of the AI CPG Workshop puts your products, customers, pricing and trade terms into one set of documents.
The list price and retailer margin you just typed would sit in those documents.
Claude, Anthropic’s AI assistant, works from those documents. Paste in a retailer’s promotion sheet and Claude already has your prices, so it runs every item at the depth the buyer proposes and shows its arithmetic.
Live online, Tuesdays at 10 AM Pacific, one hour, recorded: November 10, 17 and 24 and December 1, 2026. Needs a paid Claude subscription.
Price, seats and the full schedule are on the workshop page.
Questions before you use it
What does it cost?
Nothing. It needs no account and no email address.
Does it keep my numbers?
No. The arithmetic runs in your browser, and the numbers you enter are not submitted, saved or sent to us.
Where do the figures come from?
Only from the four numbers you enter. The calculator uses no industry average and no typical lift, so it cannot tell you how many extra units to expect, only how many you need.
Why does the retailer’s margin matter?
Fifteen percent off the shelf costs you more than 15% of your list price. With a retailer margin of 35%, it costs about 23%.
What if the retailer pays part of the discount?
Enter only your share of the discount, as a percent of the shelf price.
What if I sell through a distributor?
Enter what the distributor pays you as your list price. In the retailer margin box, enter the share of the shelf price that does not reach you. That is one minus your list price divided by the shelf price: with a $3.00 list price and a $5.49 shelf price, 45%.