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Conversion from Baume to S.G.


Q. Hi,

Would someone tell me the formula for conversion from degree baume to specific gravity?

Thanks and Best Regards,

K F Quan
- China


A. SG= 145/ (145-Be)

Sara Michaeli
    chemical process supplier


A. I have a similar formula, but as follows: = 146/ (146 - Be) Note that this is only accurate at 20 deg. C. The result from my formula will be slightly more accurate according to the published data from our sulfuric acid supplier, for these two related values. (Splitting hairs here.) Some hydrometers are graduated in either scale.

W. Carl Erickson
- Rome, New York


A. According to the "CRC Handbook of Chemistry & Physics" [link is to info about book at Amazon] of Chemistry and Physics, 145 is the correct number to use in the formulas already mentioned.

Jon Barrows, MSF, EHSSC
Springfield, Missouri

July 8, 2008

Q. Sir please explain the detail of the formula you have mentioned. What is 145 and how it is come.
Regards. Please also tell me detail theory of degree twadel and baume.
If you can provide a table of baume conversion I would be thankful to you

Raza Rahman
employee - Karachi, Pakistan

July 29, 2008

A. Hi there,

Here is the full conversion calculation,

SG = 141.5/(131.5+API)- for oils
SG = 140/(130+deg Baume) - for liquid lighter than water
SG =145/(145-deg Baume) - for liquid heavier than water

best wishes,

Ahmed Al-Terkait
- Kuwait - Arabian Gulf

February 28, 2012

A. I totally agree with Mr. Ahmed Al-Terkait.

But an educated Engineer should know there is no A R A B I A N Gulf in the world! it is always PERSIAN GULF and your money can't change the historical name which is far older than arabian countries like yours opinion!

Amir Ghods
- Tehran- Iran (North of Persian Gulf)

October 28, 2008

Q. What is 145 exactly, where did they base it?

Lawrence Rivers
- San Carlos, Phil

March 3, 2015

Q. Hi.
I've a question:
I need to know what does number 145 exactly mean in the formula = 145/ (145 - Be) ... and where did it come from?
I need it as fast as possible .

Baumé scale

All respect

Salee Al-Baradony
- Yemen ,Sana'a , Sana'a

March 2015

A. Hi. 145 is just a number that works to convert degrees Baumé to Specific Gravity. The Wikipedia article explains the origin and purpose of the Baumé scale. Good luck.


pic of Ted Mooney Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

March 6, 2015

Q. Mr. Ted Mooney,
Thanks a lot for your answer sir ...
still the question is about the number itself and not the Baume scale or the formula.
It's about how do they get to put this number, not another number ... like why we use 145 for liquids heavier than water and use SG = 140/(130+deg Baume) - for liquids lighter than water in the other formula..
Still looking for word to help as soon as possible.
Thanks again.

All respect

Salee Al-Baradony [returning]
- Yemen, Sana'a, Sana'a

March 2015

A. Hello again Salee.

Sorry, but I don't think you are going to get satisfaction. As related in the Wikipedia article, the scale originally was based on the density of various amounts of sodium chloride dissolved in water at 16 °C. But as Wikipedia relates, the scale is inexact, vague, and ambiguous, so some handbooks cite 144 for the "heavier than water" scale, and other books cite 145, and other people cite 146. You're not going to be successful in putting a fine point on it because those constants are not based on any physical quantity, they are simply people's efforts to correlate an unreliable and vague scale to the more exacting S.G. scale. Good luck.


pic of Ted Mooney Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

March 9, 2015

A. Hi Salee

As Ted says baume is "inexact, vague, and ambiguous". Even if you understand it, chances are that others will make mistakes.
The simple solution is to change to specific gravity (SG) - understood by all worldwide and no more mistakes in conversion.

Geoff Smith
Hampshire, England

March 13, 2015

Thanks for you both :
Mr Ted Mooney
Mr Geoff Smith
for your answers ..

All respect

Salee Al-Baradony [returning]
- Yemen, Sana'a, Sana'a

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