Contact us

Email: [email protected]

We read every message. We usually reply within a few days, but we cannot promise a set response time.

Helpful details to include

• Calculator questions: the calculator, the numbers you entered and the product strength from the label.
• Corrections: the page address, what you think is wrong, and a source if you have one.
• Tool suggestions: what you were trying to work out and what the tool should ask for.

We cannot give individual professional advice. Please do not send passwords, payment details or other sensitive personal information.