Milk to Foam Calculator
Cold foam that floats perfectly comes down to liquid volume. This milk to foam calculator tells you exactly how much milk and heavy cream to froth — in both fluid ounces and milliliters — for any drink size and foam level. Uses the sweet-cream style 2:1 milk-to-cream split.
Milk to Foam Calculator
Sweet-cream cold foam style — 2 parts milk : 1 part heavy cream.
| Measurement | fl oz | mL |
|---|---|---|
| Target foam volume | 2.6 | 78 |
| Total liquid to froth | 1.3 | 39 |
| Milk (2 parts) | 0.9 | 26 |
| Heavy cream (1 part) | 0.4 | 13 |
| Froth time (handheld frother) | 30–45 seconds | |
- 1. Combine milk and heavy cream in a tall jar or cup.
- 2. Froth with a handheld frother for 30–45 seconds until doubled and fluffy.
- 3. Spoon or pour over iced coffee, cold brew, or matcha.
Frothing roughly doubles volume, so liquid to froth ≈ target foam / 2. 1 fl oz ≈ 29.57 mL.
How the milk to foam ratio works
A handheld frother roughly doubles the volume of cold liquid: 2 fl oz of milk and cream frothed for 30–45 seconds yields about 4 fl oz of foam. That means you only need half the target foam volume as actual liquid. The sweet-cream split (2 parts milk to 1 part heavy cream) gives the foam enough fat from the cream to stay thick and float on top of your cold brew or iced coffee, while the milk keeps it from getting too rich.
Light foam targets about 15% of drink volume, medium targets 22%, and extra targets 30%. For a 16 oz cold brew with medium foam you want roughly 3.5 fl oz of foam, which means frothing about 1.75 fl oz of liquid — around 1.2 fl oz milk and 0.6 fl oz cream. The calculator handles all the math so you can focus on the froth.