Milk is the biggest variable cost in most espresso drinks. Convert your per-gallon price down to the ounces in one latte and you'll know exactly what each drink's milk costs.
A US gallon is 128 fluid ounces, so dividing by 128 gives the cost per ounce.
The example
Milk costs $4.50 a gallon and a 12-oz latte uses 8 oz of steamed milk.
| A | B | |
|---|---|---|
| 1 | Label | Value |
| 2 | Milk price / gallon | $4.50 |
| 3 | Ounces per latte | 8 |
| 4 | Milk cost / latte | $0.28 |
The formula
Price per ounce times the ounces in the drink:
How it works
The conversion, step by step:
- A US gallon holds 128 fluid ounces, so
B2/128is the cost of one ounce of milk. - Multiply by the ounces a latte uses (B3) to get that drink's milk cost.
- ROUND to two decimals gives a clean per-drink figure.
- Here: 4.50 ÷ 128 × 8 = $0.28 of milk per latte.
Add your shot cost and cup/lid cost to get the drink's full ingredient cost.
Try it: interactive demo
Enter the gallon price and ounces per drink — see the milk cost.
Variations
Cost for a batch of drinks
Multiply the per-drink cost by the number of lattes sold.
Switch to per-litre pricing
If milk is priced per litre, a litre is about 33.8 fluid ounces.
Pitfalls & errors
Mind your units — mixing a per-litre price with the 128-ounce divisor will overstate your cost. Use the matching divisor.
Steam wand waste and foam overpour add up; bump the ounces slightly if your baristas pour heavy.
Practice workbook
Frequently asked questions
Why 128?
Should I include foam?
How do I get full drink cost?
Stop fighting formulas. Learn them in a day.
This recipe is one of hundreds of real-world formulas we teach. Our Excel Formulas & Functions class covers lookups, logic, text, and dynamic arrays hands-on — live in Dallas–Fort Worth, Houston, Austin, Oklahoma City, Denver, or online.
See the Formulas & Functions Class