My hydrometer shows units I can't conciliate with whatever I read on the internet.

It shows from top to down:


On Internet however,the gravity should be measured in floats of the 1.xxx type.

How should I read this hydrometer?

enter image description here

  • Apparently some answers are confused. Are you just showing part of the hydrometer scale, as an example?
    – chthon
    Dec 12, 2017 at 12:17

3 Answers 3


It might be Brix or Plato, which are basically the same. To test, mix up a 10% solution of sugar: 10 grams sugar in 90 grams water. If the scale is Brix, your solution should read 10 at the calibration temperature. If the units are gravity points, it will read 40.

  • Actually, Brix and Plato are not equivalent, though the difference becomes significant only at high gravities. Here's a chart that shows this: braukaiser.com/documents/Kaiser_Brix_Plato_SG_table.pdf
    – mingos
    Dec 19, 2017 at 11:29
  • A 10% solution would be 10g in 100ml not 90ml right?
    – EnduroDave
    Dec 24, 2017 at 10:45
  • Nope. 10g sugar + 90g water = 100g total of which 10g, or 10% is sugar. Dec 24, 2017 at 16:33

The scale is sometimes called "Gravity Points" - it's the Specific Gravity value (1.xxx) without the "1." prefix. So, 1.010 is 10, 1.020 is 20,...1.100 is 100 and so on.

  • Okay, if so then my hydrometer showed 80 before fermentation and now it shows 70. From these figures the alcohol content by volume should be 1.31%, but my banana wine clearly is much stronger than that (I'd say 20% by the taste of it). Sep 15, 2013 at 15:35
  • 3
    If those are gravity points, it's a narrow range hydrometer; it only goes up to 50. I'd guess that the units are Brix or zplato. Sep 15, 2013 at 15:36
  • I agree Tobias - it could be brix also. I do have a narrow range hydrometer for FG which is why I thought gravity points. But the best solution is to test against a calibrated solution like you say in your answer.
    – mdma
    Sep 15, 2013 at 17:07
  • 6
    I'm confused -- how did you read 80 before fermentation, when the highest number on the scale is 50? Is there a different scale on the other side? Sep 15, 2013 at 22:23

The physical quantity of hydrometer reading is Gram/liter.

  • Brix and Plato are in g/100 g. A hydrometer reading from a solution is a value relative to the weight of water.
    – chthon
    Dec 12, 2017 at 12:15
  • Maybe there are hydrometers which immediately read in Brix or Plato, even then your stated value in gram/liter is incorrect.
    – chthon
    Dec 12, 2017 at 12:18
  • @chthon g/l is not impossible depending on where the hydrometer was bought. In fact I have seen one with the same scale (0-50) being a sugar scale 0–50 ounces per gallon.
    – Philippe
    Dec 12, 2017 at 14:20

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.