Technical Questions

If you have any problems or questions about using PCalc, check out the list of frequently asked questions below and, if the answer isn't there, mail me at:

or contact me via Mastodon at:

@pcalc or @jamesthomson

or via Threads at:


and I'll do my best to help.

Frequently Asked Questions

Okay, so the list here isn't exactly comprehensive! If you have a question, please let me know at the address above.

Q. I bought PCalc from Kagi before the 1st of April 2013, why do I have to pay again for PCalc 4?

A. We haven't charged for an update to PCalc since the original shareware release, about fourteen years ago. We're a small company and it's not sustainable to give away updates forever. Also, there isn't a good way to turn your existing PCalc 3 license into a Mac App Store one. We hope you understand. By buying this update, you are ensuring the product has a future.

Q. I bought PCalc from Kagi ages ago, and I have a serial number - can I just download it from the Mac App Store now?

A. No, there is unfortunately no way for Apple to know that you are an existing owner of PCalc, so you will be charged twice if you do so. If you bought PCalc through Kagi, you have to download versions from here.

Q. I bought PCalc for through the Mac App Store - when I run PCalc, it asks for a serial number, where do I find it?

A. It sounds like you have downloaded a version of PCalc intended for people who originally bought it through Kagi - the version from the Mac App Store doesn't require a serial number. You can redownload a new copy from the Mac App Store here.

Q. How can I tell apart a version of PCalc bought from the Mac App Store, and one bought from Kagi?

A. If you look in the "About PCalc" window in the app, it will say "Mac App Store" at the bottom of the window if it was purchased from Apple. Conversely, if it asks you for a serial number when you run it, it's the Kagi version.