Recipe Scaler Calculator
Scale any recipe up or down by changing the number of servings it makes.
Last updated · View algorithm, constants and default inputs (JSON)
About this calculator
Scaling a recipe is a single multiplication applied to every ingredient — but the conversion factor is easy to get backwards. Enter the original and desired servings and the factor follows.
Worked example
calculated with the default values below
Original servings 4 servings · Desired servings 6 servings · Amount of one ingredient 200 New ingredient amount 300.0000 · Scaling factor 1.5000 x · Change (%) 50.0 %
General background references
Disclaimer
These calculators give general cooking guidance. Ingredient density, oven calibration, altitude and equipment all vary, and safe minimum internal temperatures always take precedence over timings. Follow the food-safety advice issued by your national authority.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
f = S₂÷S₁; x₂ = x₁×f; Δ = (f−1)×100
- S₁
- Original servings
- S₂
- Desired servings
- x₁
- Original amount
- x₂
- New amount
- f
- Scaling factor
- Δ
- Change (%)
Ingredient amounts scale linearly by the serving factor. Seasoning, cooking time, pan size and texture may not scale linearly.
Frequently asked questions
How does changing servings from 4 to 6 affect one ingredient?
The factor is simply desired divided by original, so four to six servings gives 1.5×, and a 200 g ingredient becomes 300 g, a 50 percent increase. The same factor applies to every ingredient, but the calculator only scales the single amount you enter. Watch the direction: entering a smaller desired serving produces a factor below 1 and a negative change percentage.