Custard Ratio Calculator Formula

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

Use the Custard Ratio Calculator

Formulas Used

Total Dairy

total_dairy = servings * serving_ml

Whole Eggs Needed

whole_eggs = ceil(servings * serving_ml / (120 * custard_style))

Dairy (cups)

dairy_cups = servings * serving_ml / 240

Sugar (approx)

sugar = servings * serving_ml * 0.08

Variables

VariableDescriptionDefault
servingsNumber of Servings6
serving_mlVolume per Serving(mL)150
custard_styleCustard Style1
total_mlDerived value= servings * serving_mlcalculated

How It Works

How to Calculate Custard Ratios

Formula

Eggs = ceil(Total Dairy / (120 mL x Style Factor))

Style Factors

  • Standard baked custard: 1 whole egg per 120 mL of dairy (milk, cream, or a blend)
  • Rich creme brulee: 1 egg per 90 mL (denser, uses more yolks)
  • Light quiche: 1 egg per 180 mL (more liquid, softer set)

    • Using a higher proportion of yolks to whites produces a richer, silkier custard. Many creme brulee recipes use yolks only.

    Sugar

    For sweet custards, about 8% of the total dairy weight in sugar is a balanced starting point.

    Worked Example

    6 servings of 150 mL standard baked custard.

    servings = 6serving_ml = 150custard_style = 1
    1. 01Total dairy = 6 x 150 = 900 mL
    2. 02Eggs = ceil(900 / 120) = ceil(7.5) = 8 eggs
    3. 03Dairy in cups = 900 / 240 = 3.75 cups
    4. 04Sugar = 900 x 0.08 = 72 g (about 1/3 cup)

    Frequently Asked Questions

    Should I use whole eggs or yolks only?

    Whole eggs set firmer and are good for baked custard and quiche. Yolks only (or mostly yolks) create a richer, creamier texture ideal for creme brulee and pot de creme. Count 2 yolks as roughly 1 whole egg for setting power.

    What temperature should I bake custard?

    Bake at 325°F in a water bath (bain-marie) until the edges are set but the center still jiggles slightly. The internal temperature should reach 170-175°F. Overbaking causes curdling and a watery texture.

    Can I use all milk or all cream?

    Yes. All milk produces a lighter custard. All cream is very rich and dense. A common blend is half whole milk and half heavy cream for a balanced richness.

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    Open Custard Ratio Calculator