Buy X Get Y Calculator

BOGO and Buy 2 Get 1 Free are both special cases of a more general "buy X, get Y free" mechanic. Enter any X and Y to evaluate the exact profit impact.

Contribution profit per order

—

Customer pays

—

Total units delivered

—

Margin

—

Effective discount

—

vs. one regular-price sale

—

Volume uplift needed

—

Setting X=1, Y=1 reproduces classic BOGO. Setting X=2, Y=1 reproduces Buy 2 Get 1 Free. Any other combination (buy 3 get 2, buy 5 get 1) is evaluated with the same underlying formula.

How it works

Formulas used

Revenue = X × Unit price Units delivered = X + Y Product cost = (X + Y) × Unit cost Effective discount = 1 − [Revenue / (Regular price × Units delivered)]

Worked example

$30 unit price, $8 unit cost, buy 3 get 2 free, no fees:

Revenue: 3 × $30 = $90 for 5 units
Product cost: 5 × $8 = $40
Contribution profit: $90 − $40 = $50 (margin 55.6%)
Effective discount: 1 − (90/150) = 40%

Related calculators

Frequently asked questions

How do I decide the right X and Y for my business?

Higher Y (more free units) drives a bigger perceived deal but a bigger profit hit — use the required volume uplift figure to judge whether it is likely to pay off versus your historical promotion response.