Contact

Email

Write to us at [email protected]. Email is the only way to reach us; we do not offer phone support or live chat. We read every message and reply to as many as we can.

What you can contact us about

• A result that looks wrong — we treat calculation errors as our top priority.
• A suggestion for a new calculator or a feature for an existing one.
• Unclear or outdated content in an explanation, example or FAQ.
• Accessibility problems, such as a field your screen reader cannot announce or a control you cannot reach with a keyboard.
• Privacy questions about how the site handles information.
• Business inquiries, including partnerships and advertising.

Reporting a calculation issue

To help us check a result quickly, please include:

• The name or address of the calculator page.
• Every value you entered, including any units or options you selected.
• The result you saw and the result you expected.
• Where your expected result comes from — another tool, a textbook, a lender's quote or a manual calculation.
• Your device and browser, if the page did not display or behave correctly.

Different sources often use different assumptions, such as rounding, compounding frequency or the formula variant. Telling us your source helps us explain the difference or fix a genuine error.

Suggesting a calculator

Tell us what you're trying to work out and how you calculate it today. If there is a standard formula or an official method behind it, a reference is very helpful. We prioritize new tools by how many people need them and add a calculator only once we can publish a complete, well-explained page for it.

Before you write

Many questions are already answered on the calculator pages themselves. Each page explains its formula, walks through examples and includes a list of frequently asked questions. You can find every tool on the all calculators page.

What we can't help with

We can explain how a calculator works and what its result means, but we cannot give personal financial, medical, legal, tax or engineering advice, or tell you which decision to make. For those questions, please consult a qualified professional. See our disclaimer for more.

Your privacy when you write to us

If you email us, we receive your email address and whatever you include in the message, and we use them only to reply and to improve the site. We never need the values from your calculations unless you choose to send them. Read our privacy policy for details.