howoldisyourbodyAt-home biological age test

About 20 minutes · nothing leaves your browser

Your at-home body age test

Do the tests in any order and skip any you can’t do. Results update as you type.

The basics

Required
20 to 90
yrs
Sex at birthSets the baseline life table

Physical function

4 tests · 10 min

Strength, balance and walking speed are some of the strongest single predictors of survival in middle and older age. Wear comfortable clothes, clear some floor space, and have someone nearby for the balance tests.

0 to 10, in half pointsnot entered
pts
How to do it
  1. Barefoot, stand in a clear space. Without leaning on anything, lower yourself to sit cross-legged on the floor.
  2. Stand back up, again without support if you can.
  3. Start at 5 points for sitting and 5 for rising. Subtract 1 point every time you use a hand, forearm, knee, or the side of your leg for support. Subtract half a point for any visible loss of balance.
  4. Add the two halves together. A perfect score is 10.
Stop if you have hip or knee pain, or recent joint surgery.
10-second one-leg standCould you do it within 3 tries?not entered
How to do it
Stand next to a counter. Lift one foot and rest it against the back of your other calf. Keep your arms at your sides and eyes straight ahead. Hold for 10 seconds without touching anything. Use either leg, up to three attempts.
Seconds to stand up 5 times. Leave blank if you can’t without using your arms.not entered
sec
How to do it
Use a standard dining chair against a wall. Sit with arms crossed over your chest. On “go,” stand fully up and sit fully down five times as fast as you safely can. Stop the timer when you stand the fifth time.
Seconds to walk 4 m (13 ft 1 in) at your normal pacenot entered
sec
How to do it
Mark a start and finish line 4 meters (13 ft 1 in) apart in a hallway, with a couple of extra steps of space before and after. Start walking from a few steps behind the start line at your everyday pace, not a race. Have someone time you from the moment you cross the start to when you cross the finish. Do it twice and enter the faster time.

Body and vitals

4 measures · 5 min

Waist size relative to height tracks visceral fat better than weight alone. Take blood pressure and heart rate after sitting quietly for five minutes.

Height
ftin
Used for BMInot entered
lb
At the belly button, relaxed, after breathing outnot entered
in
How to do it
Stand up straight. Wrap a soft tape measure around your waist at the level of your belly button, snug but not pressing into the skin. Breathe out normally and read the tape. Don’t suck in.
Beats per minute, sitting, or your watch’s resting averagenot entered
bpm
How to do it
Sit quietly for 5 minutes, ideally in the morning before coffee. Find your pulse at your wrist and count beats for 30 seconds, then double it. A smartwatch’s 7-day resting average works well too.
Blood pressureHome cuff, average of 2 readingsnot entered
/mmHg
How to do it
Sit with your back supported, feet flat, arm resting at heart level, cuff on bare skin. Rest 5 minutes without talking. Take two readings one minute apart and average them. If you take blood pressure medication, enter your treated reading.

Cardiorespiratory fitness

1 estimate · 0–5 min

VO₂max is the strongest single fitness predictor of lifespan. Pick whichever way of estimating it you have available. A step test or a watch reading beats the resting heart rate formula.

not entered

Daily habits

6 questions · 2 min

Answer for a typical week over the past few months.

not entered
Minutes per week where you’re breathing hard enough that talking takes effort. Count vigorous minutes twice.not entered
min/wk
Average hours actually asleep per nightnot entered
hrs
Standard drinks per week (12 oz beer, 5 oz wine, 1.5 oz spirits)not entered
/wk
Servings per day (a fist-sized portion, or 2 cups of leafy greens)not entered
/day
not entered

How the estimate works

Your starting point is a mortality curve fitted to the current US life tables for your age and sex. In those tables, the yearly risk of dying roughly doubles every eight years of age.

Each measure you enter moves that risk up or down using the hazard ratio reported in the study listed for it. Because the life table already includes people of every fitness level, each measure is compared with a typical American of your age and sex: typical scores zero, better than typical lowers your risk, and worse raises it. Measures that overlap, such as BMI and waist size or resting pulse and VO₂max, are grouped. Within a group, the strongest signal counts in full and the others count at 40%. The combined total is then shrunk by 15% to avoid double counting across groups.

Biological age is the age at which an average person of your sex has the same yearly risk you do. Life expectancy is the average age reached on your adjusted curve. The range shows where the middle half of people with your profile would be expected to die, a reminder of how wide the spread is for any individual.

Any measure you leave blank is treated as average. The more you complete, the more the estimate reflects you rather than the population.

Read the full methodology and limitations

Evidence behind each measure

MeasureRange used (HR)Source
Sitting-rising test1.0 – 5.4Brito et al., Eur J Prev Cardiol 2014
One-leg stand1.0 – 1.84Araújo et al., Br J Sports Med 2022
Chair stands1.0 – 2.0Cooper et al., BMJ 2010 (meta-analysis)
Gait speed0.88 per +0.1 m/sStudenski et al., JAMA 2011
BMI1.0 – 2.76Global BMI Mortality Collaboration, Lancet 2016
Waist-to-height ratio1.0 – 1.9Ashwell et al., meta-analyses; NICE 2022
Resting heart rate1.12 per +10 bpmZhang et al., CMAJ 2016; Aune et al. 2017
Blood pressure1.0 – 2.0Prospective Studies Collaboration, Lancet 2002
VO₂max0.87 per +1 METKodama et al., JAMA 2009; FRIEND norms
Tobacco1.0 – 3.0Jha et al., NEJM 2013
Exercise minutes0.88 – 1.45Arem et al., JAMA Intern Med 2015
Sleep1.0 – 1.3Cappuccio et al., Sleep 2010
Alcohol1.0 – 1.7Wood et al., Lancet 2018
Fruits & vegetables1.0 – 1.18Wang et al., Circulation 2021
Social connection1.0 – 1.29Holt-Lunstad et al., Perspect Psychol Sci 2015