Wrinkles and the odd grey hair often give away our biological age, but now there may be a new way to detect a person's "heart age."
The NHS have launched an online calculator which predicts when a person will have a heart attack or stroke based on their lifestyle choices.
The tool is designed to encourage people to make healthier choices around diet, exercise and smoking in order to reduce their risk of heart disease.
The calculator asks individuals to answer basic questions, such as what height and weight they are and whether or not they smoke.
They are also asked to provide information on their own medical history, as well as their family's medical history. Questions include whether or not any immediate relatives have suffered from heart disease under the age of 60.
The calculator is a collaboration between NHS Choices, Public Health England and the British Heart Foundation.
Coronary heart disease (CHD) is the currently the leading cause of death both in the UK and worldwide.
According to the NHS, around 73,000 people in the UK die from CHD each year, and an estimated 2.3 million people in the UK are living with the condition.
Professor John Deanfield, an NHS cardiologist who helped develop the test, hopes the online tool will help to tackle these shocking figures.
"Understanding your heart age can be a real wake up call for people who might be at risk," he said in a statement.
"It can be that all important nudge to take action and make lifestyle changes to improve your heart health."
Professor Kevin Fenton, director of health and wellbeing at Public Health England, added: "Too many people are dying prematurely from preventable conditions and there is clear evidence that factors like smoking and high blood pressure play a major role in this.
"The heart age tool shows that it is never too late to make healthy lifestyle changes, giving people a chance to see the direct impact these changes can have on their heart’s health."
H/T: The Telegraph