Contact
Corrections are the most useful thing you can send.
Corrections first
If a calculator gives a wrong number, that is the most valuable message this site can receive. Please include the calculator, the exact inputs, what it returned, and what you expected — ideally with the source or software you compared against. Corrections are made quickly and the fix is recorded in the test suite so that it cannot come back.
Everything else
Suggestions for calculators that are missing, corrections to an explanation, questions about the methodology, and press or partnership enquiries all go to the same address.
Messages are usually answered within a few working days. There is no contact form here, because a form would need a server and this site deliberately does not have one — which is also why nothing you type into a calculator can be transmitted.
What we cannot help with
We cannot analyse your data for you, check your coursework, or advise on which test to use for a specific study — the decision guide is our answer to that question, and it is the same answer we would give by email.
Who you are writing to
ZW Studio LLC · support@zwstudiollc.com