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Refracto - Refractometer Calculator for Homebrewers

Refracto is a tool for homebrewers that will help you to convert your refractometer measurements during a fermentation process from °Brix to SG or °Plato. It automatically compensates the alcohol effect during fermentation.

Refracto is available on the App Store

How to use Refracto

  1. Swipe vertically to enter your initial refractometer reading, i.e. the measurement result for the original wort, just before adding the yeast.
  2. Swipe vertically to enter your current refractometer reading, i.e. a measurement result after the fermentation process has started.
  3. Swipe horizontally to switch between the computation modes. Available modes are the Standard formula, the Kleier formula -- a slightly modernized variant of the Standard formula -- and Sean Terrill’s linear and cubic formula. The Standard and Kleier formulas are best for general purpose use.
  4. You are done! In the upper section you can now see the computed values for your beer.

How to use Refracto

Computed Values

Refracto computes and immediately updates the following values whenever you change one of its input values:

  1. The resulting original gravity (OG).
  2. The estimated alcohol concentration as percent by volume.
  3. The final gravity (FG), displayed on the top as apparent gravity and as actual gravity on the bottom. The apparent gravity corresponds to a measurement with a hydrometer.
  4. The amount of sugars consumed by the yeast so far, displayed as apparent attenuation on the top and as real attenuation below.

Computed Values


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