Contact
Email is the only channel, and it reaches a person.
What is useful to include
Reporting a bug: the page you were on, your browser and version, and what the file was (format and rough size). If a conversion failed, knowing whether it failed on every file or just one narrows it down immediately.
Reporting a wrong calculation: the exact values you entered and the result you expected. Most reported "errors" turn out to be a documented assumption — such as PMI being included, or sales tax being applied after the trade-in credit — and knowing your inputs makes that quick to confirm either way.
Requesting a tool: describe the actual task rather than the feature. Knowing what you were trying to accomplish often reveals a better tool than the one being asked for.
What we cannot help with
We cannot recover a file. Nothing you process here is stored on any server, so if you converted something and lost the download, it no longer exists anywhere except on your own device.
We cannot give financial advice. The calculators show their assumptions and we are happy to explain the arithmetic, but questions about what you should do belong with a licensed professional.
Response time
This is a small site run by one person. Expect a reply within a few days rather than a few hours.