Health & Medical Calculators

Our health calculators turn everyday measurements — your height, weight, age and a few simple inputs — into numbers you can actually use: body mass index, daily calorie needs, a healthy weight range, pregnancy dates and more. They are free, work instantly in your browser, and are designed to be a helpful starting point, not a diagnosis.

What is a health calculator?

A health calculator is a tool that applies a clinically recognised formula to the details you enter and returns an estimate in seconds. For example, a BMI calculator divides your weight by the square of your height to estimate whether your weight sits in a healthy range, while a calorie calculator uses your age, sex, weight and activity level to estimate how much energy your body uses each day. The maths is standardised, so the same inputs always produce the same result — which makes calculators a quick, private way to check where you stand before a consultation.

How to use the calculators

Every tool follows the same simple flow:

Enter your details, read your result and the range it falls into, then — if anything is outside the expected range or you simply want clarity — send it to our team using the form on this page. A specialist can explain what the number means for your health and, if useful, suggest the right check-up or treatment.

Which health calculators are available?

The most widely used tools cover weight, metabolism, heart health and pregnancy:

How accurate are online health calculators?

Calculators are reliable for the maths, but they work from population averages and cannot see the full picture. BMI, for instance, does not distinguish muscle from fat, so a very muscular person can read as “overweight” while still being healthy. Calorie estimates assume an average metabolism, and pregnancy dates assume a regular cycle. Treat every result as a guide that highlights questions worth asking — not a diagnosis.

When should you speak to a doctor?

Consider a consultation if a result falls outside the healthy range, if it changes quickly, or if it comes alongside symptoms such as breathlessness, pain, unexplained weight change or fatigue. You should also seek personalised advice before starting a new diet, exercise programme or treatment plan. Our international patient team can arrange the right specialist, a tailored check-up or a second opinion, and guide you through travel and scheduling.

Frequently asked questions

Disclaimer: These calculators and the information on this page are provided for general educational purposes only and do not constitute medical advice, diagnosis or treatment. Always consult a qualified healthcare professional about your individual situation. In an emergency, contact your local emergency services immediately.