BOGO Calculator Formula

Understand the math behind the bogo calculator. Each variable explained with a worked example.

Formulas Used

Effective Price Per Item

effective_per_item = pair_cost / 2

Total Cost

total_cost = pair_cost * num_pairs

Total Savings

total_savings = item_price * bogo_pct / 100 * num_pairs

Variables

VariableDescriptionDefault
item_priceItem Price(USD)12.99
bogo_pctSecond Item Discount(%)50
num_pairsNumber of Pairs1
pair_costDerived value= item_price + item_price * (1 - bogo_pct / 100)calculated

How It Works

How BOGO Deals Work

Buy-one-get-one promotions give a discount on the second item when you buy two. The discount on the second item can range from a small percentage to 100% (completely free).

Formula

Pair Cost = Full Price + Full Price x (1 - BOGO Discount / 100)

Effective Per Item = Pair Cost / 2

Worked Example

A store offers BOGO 50% off on items priced $12.99. You buy 1 pair.

item_price = 12.99bogo_pct = 50num_pairs = 1
  1. 01First item: $12.99 at full price
  2. 02Second item: $12.99 x (1 - 0.50) = $6.50
  3. 03Pair cost = $12.99 + $6.50 = $19.49
  4. 04Effective per item = $19.49 / 2 = $9.74
  5. 05Savings = $12.99 x 0.50 = $6.50

Ready to run the numbers?

Open BOGO Calculator