Starting 13 January 2026 I am moving the site to new system.
The content part (free online tutorials and research) is available normally.
The user account section is paused for a few days until I complete migrating all user data and test everything.
This means you cannot login or order calculators now.
If you need to re-download a calculator you bought in the past, contact me.
Contact me to Get a Calculator
If you want a calculator and don't want to wait until orders are restarted:
- Contact me using the online contact form. Let me know which calculator(s) you want.
- I will send you payment link by email.
- Click the link and pay.
- I will get a notification of your payment automatically, so you don't need to let me know you have paid.
- I will send you the calculator file(s) by email.
I try to respond quickly during European and US East Coast business hours. It may take longer at other times, but typically not more than 24 hours.
See overview of all available calculators.