Excel Wrapper

Pre-compiled Binaries for windows

Automated Installation

As of October 2016, the Excel wrapper for Microsoft Windows can be installed from the Windows package as described on the page on installation packages. Please refer to the documentation there for issues related to the installation process on Windows.

[1]If you get security warnings after you installed the CoolProp add-in, you can try adding the installation folder to your trusted directories: Got to File->Options->Trust Center->Trust Center Settings...->Trusted Locations and add the folder where your xlam-file lives. This is most likely C:\Users\username\AppData\Roaming\Microsoft\AddIns\.

Manual Installation

For a manual installation,

  1. Get the shared libraries at shared_library/Windows/32bit__stdcall and shared_library/Windows/64bit, put the DLLs into a folder of your choice and rename them to CoolProp_stdcall.dll and CoolProp_x64.dll. Make sure to add that folder to your path. Technically you only need the DLL that matches your system architecture (CoolProp_stdcall.dll = 32-bit, CoolProp_x64.dll = 64-bit), but it can’t hurt to copy both if you don’t know which system architecture version you have. The Excel macro will select the correct one and use it.
  2. Download the xla and xlam files from MicrosoftExcel and activate the add-in from Excel as described below. and copy the files to a convenient accessible location.
  3. The TestExcel.xlsx from MicrosoftExcel can be copied to a working directory in My Documents.
  1. Open Excel
  2. Go to the menu File–>Options–>Add-Ins
  3. At the bottom, select Manage: Excel Add-ins, then click the Go... button
  4. Click the Browse button on the Add-in Manager panel
  5. Browse to the file CoolProp.xlam you downloaded and select it
  6. Make sure the CoolProp Add-in is selected (box checked) and close the Add-in Manager.
  7. Open the file TestExcel.xlsx and try to re-evaluate one of the cells; the CoolProp formulas should all be working now. (To recalculate the entire worksheet, press Ctrl-Alt-Shift-F9 ) [1]

Alternate DLL Location - Some environments, lock down the folders included in the binary search path for normal users for security reasons. If this is the case, you will need to put the DLL files in an alternate location (possibly on a shared network location for all users). Follow the instructions below:

  1. Place the CoolProp DLL files in the alternate location
  2. Place the CoolProp xlam file in a writable location and open it.
  3. You will get an Excel error, File not found - CoolProp_stdcall.dll. Clicking Ok on the error will only clear the first of many. Press and hold the ``Enter`` key until all of the errors clear.
  4. Make sure that the Developer ribbon is visible on the main menu. If not
    • Go to File | Options on the main menu and select Cusomize Ribbon
    • Make sure that the Developer main tab is checked (ON)
  5. Open the Visual Basic editor and use Edit | Replace to replace all occurances of CoolProp_stdcall.dll with the full path to the alternate location for your DLL files, making sure to press the save button (disk image) or File | Save before exiting the VBA editor.
  6. Save the CoolProp.xlam file.
[3]If you are having problems with the path to the XLAM in your worksheet appearing as the complete path to the xlam (but not the correct path), you might need to go into Data->Update Links in Excel, select CoolProp.xlam, and select Change Source... and select the location of your xlam file. That should update all the links.

Pre-compiled Binaries for OSX


There are now both 32-bit and 64-bit versions of Microsoft Excel on OSX. You need to make sure that your bitness of the shared library for CoolProp (and perhaps REFPROP) match that of Excel.

Part 1:

There are several ways to determine the bitness of your Excel version. The easiest is to open a terminal, and do something like:

Ians-Mac-mini:~ ian$ file /Applications/Microsoft\ Excel.app/Contents/MacOS/Microsoft\ Excel
/Applications/Microsoft Excel.app/Contents/MacOS/Microsoft Excel: Mach-O 64-bit executable x86_64

Or you can go into Excel->About Excel. If version is greater than 15.24, you are running a 64-bit version of Excel.

Part 2:

We need to convince Microsoft Excel to load our shared library, and it seems the only place it is willing to look for shared libraries is in the folder /Users/${USER}/Library/Group Containers/UBF8T346G9.Office, where ${USER} should be replaced with your user name. This is because Excel is now sandboxed.

Following http://apple.stackexchange.com/a/106814, save these contents as the file ~/Library/LaunchAgents/my.startup.plist (obviously replace ihb with the appropriate user name):

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
  <string>launchctl setenv DYLD_LIBRARY_PATH "/Users/ihb/Library/Group Containers/UBF8T346G9.Office"</string>

This .plist will be run as soon as the computer starts, and will set the DYLD_LIBRARY_PATH environmental variable, and Microsoft Excel will then read this variable, and be willing to load your shared library

Make sure to log out and log back in to have this .plist take effect.

Part 2a (optional):

If you want to add additional paths to the terminal, you can add a line like this to your ~/.bash_profile for instance to append paths to the DYLD_LIBRARY_PATH variable. It calls launchctl to extract the DYLD_LIBRARY_PATH environment variable and prepends /another/path to it:

export DYLD_LIBRARY_PATH="/another/path:`launchctl getenv DYLD_LIBRARY_PATH`"

Part 3:

Download the xlam from MicrosoftExcel or the development version from MicrosoftExcel.

Place XLAM file in /Users/${USER}/Library/Group Containers/UBF8T346G9.Office, where ${USER} should be replaced with your user name

Follow the below instructions depending on the version of Excel you have. If you can’t figure out what version of Excel you have, it’s fine to have both 32-bit and 64-bit versions of the .dylib sitting next to each other.


Download pre-compiled release binaries for OSX from shared_library/Darwin/32bit/. Development binaries coming from the buildbot server can be found at shared_library/Darwin/32bit/.

Place the downloaded file libCoolProp.dylib in the folder /Users/${USER}/Library/Group Containers/UBF8T346G9.Office too, but RENAME it to libCoolProp_32bit.dylib (this is to ensure that there is no name clash with the standard 64-bit shared library).


Download pre-compiled release binaries for OSX from shared_library/Darwin/64bit/. Development binaries coming from the buildbot server can be found at shared_library/Darwin/64bit/.

Place the downloaded file libCoolProp.dylib in the folder /Users/${USER}/Library/Group Containers/UBF8T346G9.Office.

Part 4:

Open Excel, go to Tools/Add-ins.... In browse, go to the folder listed above with the BF8T346G9.Office in it. Select CoolProp.xlam.

Part 5:

Add this to a cell:


make sure you get something like 373.1242958 K.


  • If it doesn’t work and you get error number 53, it might be because you have a 64-bit .dylib file and you want a 32-bit .dylib file. For instance when you run the file command on your .dylib, you should see something like:

    $ file libCoolProp_32bit.dylib
    libCoolProp.dylib: Mach-O dynamically linked shared library i386

    the i386 is the important bit, that indicates that the shared library is 32-bit.

REFPROP support on OSX

You can also call REFPROP through the Excel wrapper of CoolProp, but it requires a few tweaks to work properly

  1. The refprop dylib (with the correct bitness!), as well as the fluids and mixtures folders of REFPROP should be placed in the folder refprop inside /Users/${USER}/Library/Group Containers/UBF8T346G9.Office. Make sure the shared library is called librefprop.dylib.
  2. An environment variable called COOLPROP_REFPROP_PATH should be set to the folder /Users/${USER}/Library/Group Containers/UBF8T346G9.Office/refprop (see above about how to do that in a .plist file). The CoolProp xlam, on loading, will query this environment variable to determine which path to use for REFPROP. It seems from my testing that this path MUST be a subfolder of /Users/${USER}/Library/Group Containers/UBF8T346G9.Office due to the sandboxing.

User-compiled Binaries

Common Requirements

Compilation of the Excel wrapper requires a few common wrapper pre-requisites


The instructions here are for a 64-bit windows system that will compile both 64-bit and 32-bit versions of the DLL:

# Check out the sources for CoolProp
git clone https://github.com/CoolProp/CoolProp --recursive
# Move into the folder you just created
cd CoolProp
# Make a build folder for the 32-bit DLL
mkdir build/32bit__stdcall && cd build/32bit__stdcall
# Build the MSVC project using CMake
# Make the shared library
cmake --build . --config Release
cd ../..
# Make a build folder for the 64-bit DLL
mkdir build/64bit && cd build/64bit
# Build the MSVC project using CMake
cmake ../.. -G "Visual Studio 10 Win64" -DCOOLPROP_SHARED_LIBRARY=ON
# Make the shared library
cmake --build . --config Release
cd ../..
# Copy the generated DLL
copy build\32bit__stdcall\CoolProp.dll c:\CoolProp
copy build\64bit\CoolProp.dll c:\CoolProp