Pie Crust Ratio Calculator Formula

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

Use the Pie Crust Ratio Calculator

Formulas Used

Flour

flour_total = flour_weight * crust_type * pow(pan_diameter / 9, 2)

Fat (Butter/Shortening)

fat_total = flour_weight * crust_type * pow(pan_diameter / 9, 2) * 2 / 3

Ice Water

water_total = flour_weight * crust_type * pow(pan_diameter / 9, 2) / 3

Salt

salt_total = flour_weight * crust_type * pow(pan_diameter / 9, 2) * 0.02

Variables

VariableDescriptionDefault
pan_diameterPie Pan Diameter(inches)9
crust_typeCrust Coverage1
flour_weightFlour for Single Crust(grams)180
scaleDerived value= crust_type * pow(pan_diameter / 9, 2)calculated

How It Works

How to Calculate Pie Crust Ingredients

The 3:2:1 Ratio

3 parts flour : 2 parts fat : 1 part water (by weight)

This classic ratio produces a flaky, tender crust. The flour provides structure, cold fat creates flaky layers, and ice water binds the dough.

Scaling for Pan Size

The base recipe is calibrated for a 9-inch pan. Scale by the square of the diameter ratio: (pan / 9) squared. A double crust uses twice the material.

Tips

Keep butter and water ice cold. Overworking the dough develops gluten, making the crust tough instead of tender.

Worked Example

A double-crust pie in a 9-inch pan, 180 g flour base per single crust.

pan_diameter = 9crust_type = 2flour_weight = 180
  1. 01Scale factor = 2 x (9/9)^2 = 2
  2. 02Flour = 180 x 2 = 360 g
  3. 03Fat = 360 x 2/3 = 240 g (about 1 cup butter)
  4. 04Water = 360 / 3 = 120 g (about 1/2 cup)
  5. 05Salt = 360 x 0.02 = 7.2 g (about 1.5 tsp)

Ready to run the numbers?

Open Pie Crust Ratio Calculator