Health Calculators

A1C, BMI and more — quick, clear estimates for everyday health questions.

ziffaro’s health calculators give you a fast, clear estimate for the everyday numbers that come up between doctor visits — like converting an A1C to an average glucose reading. Each tool shows the formula or standard it uses and, where it matters, links to the official source it is based on, so you can see exactly how the result is reached. Everything runs right in your browser, so your inputs stay on your device, and every tool is free with no account. Results are informational only and are not medical advice or a diagnosis. Your numbers depend on your individual situation, so always talk to your doctor about what they mean for you and before making any change to your care. These tools are meant to help you understand a figure you already have — for instance, seeing the average glucose that matches an A1C result from your lab — rather than to screen for or diagnose any condition. They never replace a proper test, an examination or a conversation with a qualified clinician who knows your history. More health calculators are added carefully, and only where a clear, well-established formula or an official standard exists to base them on.