# What unit does my hydrometer show?

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

It shows from top to down:

00
10
20
30
40
50

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

How should I read this hydrometer?

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

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 Dec 19, 2017 at 11:29
• A 10% solution would be 10g in 100ml not 90ml right? 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
• 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
• 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. 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. 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. Dec 12, 2017 at 14:20