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RP Fiber Calculator – Get it Here

Download and Installation

This software works on computers running under Microsoft Windows. (Any Windows version since Windows XP should do, but not within a virtual machine.) It's very simple: just download the installation file by clicking on this button:

Then run this file to get the software installed.


  • If the original version has expired, subsequently asking for an activation code, you can download the current version and install it over the old one in order to keep it running for free.
  • If you use Windows 8 or 10 (or Internet Explorer on other systems), you might see a message like “Windows SmartScreen prevented an unrecognized app from starting ...”. You can then press on “More info”, verify the publisher (RP Photonics AG) and choose “Run anyway”, but only if you are sure that you downloaded the program from our website, i.e., you got the original software.

If you have any problem with the download or installation, we will be grateful to learn about it via an e-mail. (That applies also to users of the free version.)

We assure you that we have not intentionally or knowingly equipped our software with any hostile functionality, for example for damaging anything on your computer, infecting it with malware or violating your privacy. However, we obviously have no control over what modified (possibly infected) software might be illegally offered for download on other websites. And we cannot take responsibility for criminal attacks from third parties if these cannot be prevented by us despite acting with due care.

Update History

Here we keep you informed on the released versions. (We occasionally offer updates when we identify and remove bugs or add new features.) The software also occasionally displays the table below, and offers to download an update if it is available.

Instead of version numbers, we just list the release dates in chronological order.

Updates on the Free Version

2014-03-17The first release has been published. Enjoy it!
2014-05-30Here is an update – with no major new features, but various improvements.
2014-06-21A minor update. There is now a feedback button, which brings you to our new feedback form. We are grateful for your hints concerning how to make the software even better!
2014-07-10Some minor improvements have been implemented.

Fixed a problem leading to the error message “Interface DLL missing”.

2015-05-12Terrible bug detected and fixed: the feedback form was not working over a longer time! We are very sorry and ask all users to try again giving us their warmly welcome feedback!
2017-10-13Another terrible bug was introduced on 2017-09-28 when updating the software: the mode solver did not work anymore. If you got that version, please download the new one. Sorry for the problem!
2018-05-28The software now also works in virtual machines – for example, when you want to use it on a Mac.
2019-05-06Fixed a problem with a missing material data file.
2020-01-02Fixed a serious bug: effective mode areas of modes with l > 1 where displayed 4 times too large.
2021-03-02The PRO version was erroneously downloaded instead of the free version. It contained a bug (see below).

Updates on the PRO Version

2014-06-10The PRO version has been released!
2017-10-13Some small improvements.
2020-01-02Fixed a serious bug: effective mode areas of modes with l > 1 where displayed 4 times too large.
2021-03-02Fixed a serious bug, affecting calculations of fiber coupling and end reflections. (It was not there from the beginning, but introduced a while ago.)

If you download an updated version, just install it over the previous version. (You do not need to uninstall the old version.)

Other Notifications

Here we occasionally publish other notifications, which may be relevant to users of RP Fiber Calculator, and are also displayed in that software.

Notifications on the Free Version


The PRO version of this software is now available! It has a lot of additional features, which you find explained on our website. Also, users obtain competent technical support – including general technical advice on fiber optics.

For commercial use, the first license costs 3850 CHF including 4 hours of technical support, and further licenses for the same company cost 1250 CHF including 2 more hours of support.

For non-commercial use, the first license costs 2550 CHF including 2 hours of technical support, and further licenses for the same working group cost 700 CHF including one more hour of support.

(Details were updated on 2022-12-27.)

In Switzerland, 7.7% VAT are added; foreign customers are responsible for paying taxes in their country.

If you need a formal quotation or if you have any questions, please contact us.


For the PRO version, we now offer another license type: one-year licenses, costing 30% of a perpetual user license. If you are not sure for how long you will this software, this might be a more attractive offer.

Notifications on the PRO Version

There are no notifications yet.

License Conditions

The installation of the software requires you to accept our license conditions. These are very generous; the essentials are:

  • You can use that software even for commercial purposes without paying anything.
  • We do not require you to register with us as a user.
  • You are not allowed to give the software to other persons or institutions. Every user should download it himself from the RP Photonics website. This is to make sure that everyone gets the original software (not one with malware added by another party!) and also the latest version.
  • We fully respect your privacy. Our tool will only occasionally check for available updates or other notices on our server, and allows you to get further information in your web browser. We will not try to identify the users of our free software.

Your feedback is welcome – for example, if you report bugs or suggest improvements. Please understand, however, that we cannot offer further technical support for a totally free product. Of course, you may obtain paid technical consultancy from RP Photonics.

Enjoy it and Tell Others!

What we hope is

  • that you will enjoy this convenient tool,
  • that you will tell others about it (e.g. via e-mail, websites, social media), who can also profit from it, and
  • that you will consider to purchase some of our other software products – namely the extremely powerful and flexible RP Fiber Power software, with which one can do much more.

Another offer: we have interesting newsletters which you can subscribe to. One of them (the RP Photonics Software News) is specially on software issues.