Questions, feedback & corrections
Contact us
Found a calculation that needs a closer look, or have an idea for a useful tool? Here’s how to reach us and what to include.
Calculator corrections
Help us reproduce the result
A clear example makes a calculation easier to check. Include the following details in an error report:
- Calculator page. The tool name and its page address.
- Inputs and settings. Sample numbers, units, dates and the calculation mode you selected.
- Actual and expected results. What the tool showed and what you expected instead.
- Your reference. A formula, worked example or source supporting the expected answer.
- Your device. The browser you used and whether you were on a phone, tablet or computer.
Use sample values. Please leave out passwords, account numbers, identity documents and personal medical records.
Other ways your feedback helps
Suggest a calculator
Tell us the question you want to solve, the inputs you would expect and a simple example of the result.
Report a website problem
Describe the page, what you tried and what happened. Include the browser and device details so the issue is easier to reproduce.
Ask about embedding a tool
Start with the calculators for your site. If you have a question, mention the calculator and the website where you plan to use it.