On this page
How the calculation works
Here is the exact math behind your result, using your own numbers.
Measure your height again
Most people lose some height with age, from changes in the spine and posture. Using the height from your driver's license or from decades ago makes BMI read too low. Measure it now, standing against a wall: how to measure height accurately.
If you can't stand straight or at all, height can be estimated from knee height. BMI without a height measurement.
What research says about BMI after 65
Large studies of older adults have found that the lowest risk of death isn't always in the 18.5–24.9 range. A 2014 analysis of studies in people aged 65 and over found the risk of death was lowest at a BMI of about 27 to 28, and higher below about 23 and above about 33.1 This doesn't mean gaining weight is healthy. It suggests that in later life, being underweight or losing weight can be a bigger concern than a BMI in the mid-to-high 20s.
Talk to your doctor about what BMI range makes sense for you, since the official categories haven't changed for older adults. Raise it sooner if you're losing weight without trying. When to see a doctor.
When BMI can mislead
- Muscle loss. Muscle naturally decreases with age. Someone can have a "healthy" BMI while carrying little muscle and more fat than it suggests.
- Unintended weight loss. Losing weight without trying, for example 5% of body weight over 6 to 12 months, is worth mentioning to a doctor at any BMI.
- Fluid. Swelling in the legs, from heart or kidney conditions, adds weight that isn't fat or muscle.
Frequently asked questions
What is a healthy BMI for a 70-year-old?
The official adult range is 18.5 to 24.9.2 Some research suggests slightly higher BMIs aren't linked with extra risk in older adults, while a low BMI is.1 Your doctor can advise on your own target.
Should I use my old height or my height now?
Your height now. Using an older, taller measurement makes your BMI look lower than it is.
Sources
This page is for education and is not medical advice. A doctor can tell you what your BMI means alongside your overall health.
