Contact
Questions about a calculator, found a mistake, or have an idea for a new tool? We’d like to hear from you. Gumbmann & Co. is based in Minnesota and we read every message.
- Email: gumbmannandco@gmail.com
- Phone: (612) 568-2288
- Location: Minnesota, serving the Twin Cities
We usually reply within one to two business days. If you’re reporting a calculator problem, tell us which calculator you used and the numbers you entered so we can check it.
Our calculators give estimates for planning and learning. They aren’t medical, financial, tax or legal advice. See our Privacy Policy for how we handle information.