How to use this calculator
- Enter or choose recipe makes.
- Enter or choose you need.
- Enter or choose ingredients (one per line, quantity first).
- The scaling factor updates as you type. Use Copy result or Share to keep it.
Method
Factor = New servings ÷ Original servings; Scaled quantity = Original quantity × Factor
- Original servings
- what the recipe as written makes
- New servings
- what you need to make
Worked example
- Factor = 10 ÷ 4 = 2.5.
- Flour: 500 × 2.5 = 1,250 g; eggs: 2 × 2.5 = 5; milk: 250 × 2.5 = 625 ml.
- Salt: ½ × 2.5 = 1.25 tsp.
To serve 10 instead of 4, multiply everything by 2.5: 1,250 g flour, 5 eggs, 625 ml milk and 1.25 tsp salt.
What the result means
Weights and volumes scale exactly. Seasoning, leavening and cooking times often do not: scale salt, spices and raising agents a little below the factor and adjust to taste, and expect larger batches to need different pans and timings.
Assumptions and limits
- Every ingredient scales in direct proportion.
- Units are not converted; a scaled 1.25 tsp stays in teaspoons.
- Countable items such as eggs may need rounding to a whole number.
Questions
How do I scale a baking recipe to a different tin?
Use the ratio of tin areas (or volumes for deep tins) as the factor: enter the old and new areas instead of servings.