Method Deck / cooking

Recipe scaling

Scales a list of ingredient quantities from an original serving count to a desired serving count.

Published for review. The Founder is checking every card himself; anything he strikes comes down the same hour.

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Inputs

original_servings (number, servings, required) min 0 : Servings the original recipe makes
desired_servings (number, servings, required) min 0 : Servings wanted
ingredients (array, required) : List of {name, quantity, unit} ingredient entries to scale

Outputs

scale_factor: desired_servings / original_servings
scaled_ingredients: Ingredient list with quantity multiplied by scale_factor

Steps

scale_factor = desired_servings / original_servings.
For each ingredient, scaled_quantity = quantity * scale_factor, rounded to 2 decimals.
Unit and name pass through unchanged; only quantity is scaled.

Constants

None.

Sources

Recipe yield scaling technique (Standard culinary reference practice (e.g. The Professional Chef, Culinary Institute of America, chapter on recipe conversion), 2026-09-30T19:50:00Z) - This card performs the standard linear scaling arithmetic; it does not adjust for non-linear items such as leavening or spice at extreme scale changes.

Worked example and test vectors

Name	Inputs	Answer
worked example	`{"original_servings":4,"desired_servings":6,"ingredients":[{"name":"flour","quantity":200,"unit":"g"},{"name":"sugar","quantity":100,"unit":"g"},{"name":"eggs","quantity":2,"unit":"count"}]}`	300 g flour, 150 g sugar, 3 count eggs
test vector: fractional scale down	`{"original_servings":12,"desired_servings":5,"ingredients":[{"name":"butter","quantity":240,"unit":"g"},{"name":"chocolate chips","quantity":360,"unit":"g"}]}`	100 g butter, 150 g chocolate chips

Published card

Address: e398b192aae298b288e1a80341479b1e
Made at: 2026-09-30T22:39:30.722Z
Method sha256: 2da2b22b66d471382c776fdd18187e692cf541929631c0967a314d3c82e72d18

Download recipe-scaling.card.json Download recipe-scaling.cjs