Pie Crust Recipe Calculator

A standard 9-inch single-crust pie shell uses 1.25 cups of all-purpose flour, and the classic ratio by weight is roughly 3 parts flour to 2 parts fat to 1 part water. In practice the fat runs a little more generous than that strict ratio suggests.

The exact recipe scales by the pie dish area, since you need more dough to cover a larger circle.

scale_factor = (desired_diameter / 9)²

A 10-inch pie has an area 24% larger than a 9-inch pie, not 11% larger as people assume from the diameter difference.
This is why store-bought 9-inch crusts always seem too small for the 10-inch dish hiding in the back of the cupboard.

Base amounts for a 9-inch single crust:

• All-purpose flour: 156 g (1.25 cups)
• Cold butter (or shortening): 113 g (1/2 cup, 8 tbsp)
• Ice water: 45-60 ml (3-4 tbsp)
• Salt: 1/2 tsp

For an all-butter crust, the fat percentage is about 72% of flour weight.
For a shortening crust, the fat is typically 64% of flour weight. Shortening is 100% fat while butter is about 80%, so you need less shortening by weight.
A half-and-half blend lands at 68%, the plain average of the two.

Butter produces better flavor and a flakier, less greasy crumb.
Shortening produces a more tender crumb that is easier to roll.
A 50/50 blend gets you both.

How wide to roll it

The number nobody prints on a recipe. A bottom crust has to cover the base, climb the wall, and hang over the rim, so the rolled circle needs to be the dish diameter plus twice the depth plus about an inch of overhang. For a 9-inch dish 1.25 inches deep that is 12.5 inches of rolled dough, which is why a 12-inch round always ends up slightly short at the back.

A top crust is a different shape of problem. It only has to reach past the rim and meet the bottom’s overhang, so two inches over the dish diameter is plenty. That is also why a double crust should not be split into two equal discs: the bottom needs roughly 55% of the dough and the top 45%. Halve it evenly and you will be stretching the bottom to reach, which is exactly how a crust shrinks down the wall in the oven.

Water

The cold water is the variable one, because humidity and flour absorption move around a lot.
Always add water one tablespoon at a time until the dough just barely holds together when squeezed.
Too little water and the crust crumbles; too much and it becomes tough.

Butter is already about 16% water by weight, which is fat that arrives with its own moisture. An all-butter crust therefore takes noticeably less added water than a shortening crust of the same flour weight, so start at the low end of the range and stop early.

Resting in the refrigerator for at least 30 minutes after mixing is not optional. It lets the gluten relax and makes rolling out dramatically easier.