Messages go straight to the person who builds and writes this site — there is no support queue in between, and no one else to route it to. Replies can take a while; everything gets read. Three kinds of message get priority.
- A result looks wrong. Tell us the calculator name, the exact inputs you used, the result you got, the result you expected, and the source you are comparing against. This is the most useful message you can send us, and it gets fixed fastest.
- A calculator is missing. Tell us what you needed to compute and what you had to do instead. Requests from working practitioners shape what we build next.
- Something is inaccessible. Tell us the page, your browser and your assistive technology. See our accessibility statement.
Use the form below. It reaches the same person; no address is published on this site, which is the only reliable way to keep a small site’s inbox usable.
What we cannot do
We cannot check your specific project, size your specific system, review your drawings, or advise on your specific financial or medical situation. Those require a licensed professional who can see the whole context and take responsibility for the result. What we can do is explain the method, cite the standard, and make sure our arithmetic is right.
Before you write about a discrepancy
Check the assumptions section on the calculator page first — most reported discrepancies turn out to be a difference in an assumption (a code edition, a rounding convention, a nominal versus actual dimension, an annual versus periodic rate) rather than an arithmetic error. If our assumption is stated and yours differs, tell us anyway: an assumption we have to explain twice is usually one we should let you change.
Postal address
For legal notices, business correspondence and anything that has to arrive on paper:
4Internet, LLC
8275 South Eastern Ave, Suite 200-265
Las Vegas, NV 89123
United States
Post is not the fast route for a calculation error — the form above reaches the same desk in seconds, and a correction sent that way is usually live the same week.
