Density by GOST 3900-85 and GOST R 50.2.076-2010

This program was designed to recalculate the density of petroleum products for different temperatures according to GOST 3900-85 (the base temperature is +20ºC). It also has a calculator for converting the volume into mass and vice versa.

In addition to GOST 3900-85, another one is used to calculate the density: GOST R 50.2.076-2010 with base temperature +15ºC. The program works with the GOST too. From the second version the program can recalculate density from GOST units to API Gravity degrees.

Program version : 2.0 (february 2018).

Program for density calculation by GOST 3900-85 and GOST R 50.2.076-2010


The program does not require installation. Just download the DensityByGOST.7z archive on your computer (if the link doesn't work, try this link) and unpack it into a folder (you may need a free 7-zip program to unpack it).

What's in the archive :

  1. densitygost.exe - the program itself
  2. tablegost3900.txt - density conversion table from GOST 3900-85
  3. settings.ini - the program itself will create the file. It stores your settings
  4. Help folder - it's for files, pictures and CSS of the help contents

For the correct operation of the program, two files are sufficient: densitygost.exe and tablegost3900.txt. They should always be stored together, remember this when transferring the program to a USB flash drive or to another folder.


The program works with the following units :

To change units, you can use the context menu of the unit field (right mouse button) or double-click on this field (units will vary in a circle). If you check the "Recalculate when changing units" checkbox in the context menu, the program will recalculate the value in the unit field "on the fly." In settings, you can change the units for all tabs of the program at once.

Program for density calculation by GOST 3900-85 and GOST R 50.2.076-2010


For calculations in accordance with GOST 3900-85 the program uses a table from it. The entered density value is interpolated, and the entered temperature value is rounded to 0 or 5 of the first decimal place. For example, temperatures +4,8ºC, +4,9ºC, +5,0ºC, +5,1ºC, +5,2ºC will be converted to +5,0ºC, and temperatures +5,3ºC, +5,4ºC, +5,5ºC, +5,6ºC, +5,7ºC to +5,5ºC. The maximum error with this rounding is 0,1% (in the zone of negative temperatures of low densities). When operating in the MGO and IFO density range the error does not exceed 0,02%.

In GOST R 50.2.076-2010 there are both tables and formulas. The program works with formulas. The maximum discrepancy with the tables does not exceed 0.1%.

To convert density to and from API Gravity (60°F) the program uses tables and formulas from the GOSTs instead of the ASTM tables. This section was included in the program for rough estimate of correlation between the density standards in the absence of the ASTM tables. It is worth noting that GOST R 50.2.076-2010 almost completely coincides with the ASTM tables 54A, 54B and 54D. Concerning GOST 3900-85 the error does not exceed 0,5% when using the GOST for density converting.


Although the author tried to be careful when moving the table from GOST to the program, errors are possible. Moreover, the table itself comes across annoying typos. The program provides the ability to edit the density table, which is a normal txt file. It is in the same folder as the program and is called tablegost3900.txt. You can edit the file by any convenient program which understands this format, for example, Notepad.

Edit table from GOST 3900-85

Before editing, be sure to back up the tablegost3900.txt. The table in the file is a set of strings of the type: #+019,5 *05000499,0 *05100509,0 *05200519,0 *05300529,0...... , where :

When editing it's important to remember the following :

Before saving the table after editing, make sure that there are no unnecessary characters and lines (even empty and EOL). For verification, disable the "line wrapping" mode in your editor - all the symbols should be carefully aligned under each other.