Grip Strength Calculator
Compare your best hand grip reading with NHANES population reference values for your age, sex and group.
What it does
Hand grip strength is one of the simplest measures of whole body strength there is, and it is used as a screening marker for frailty and for the loss of muscle mass that comes with age. The CDC measurement protocol in the national health survey is short: a dynamometer, three tries per hand with a minute between repeats, and the best result for each hand is the one that counts.
The numbers to compare against come from the same survey. The CDC analysis of more than thirteen thousand adults gives reference percentiles by age, sex and ethnic group, and a second study gives the age band means for the dominant hand taken as the best of three tries. Both are population distributions, and this page uses them to place a reading in context.
The protocol matters more than it sounds. The handle is adjusted to the hand, the subject stands with the arm at the side and the elbow straight, the squeeze is made while breathing out, and the result is a force in kilograms. Change any of that and the number stops being comparable with the reference tables.
There is a second, separate way of summarising a grip test, the combined value, which is the best of the right hand plus the best of the left hand. It is not the same as the strongest single hand, and the reference tables in this page are for the dominant hand, so the two should not be mixed.
What the numbers can and cannot say is the last point. A grip strength below a reference value is a flag, not a diagnosis, and it can reflect arthritis, a shoulder problem, nerve compression, medication or simply a bad day. The international review that also supplies age band reference values makes the same point: these are distributional benchmarks.
How to use
- Pick the units you measured in.
- Enter your age and your sex.
- Choose the group that matches the reference values you want to use.
- Enter the best of three tries with your dominant hand.
- Read the tenth percentile for your group and how far above or below it you are.
- Read the age band mean and your share of it.
Formula
- Grip
- The maximum force of the dominant hand, in kilograms, from the best of three tries.
- P10
- The tenth percentile of the NHANES reference population for that age, sex and group.
- Age band mean
- The average dominant hand best of three for the NHANES age band.
The reference percentiles are published for ages 10, 20 and every decade to 70, so the tool uses the nearest published age and says so. The mean and the percentile come from two different analyses of the survey with different summaries, so they are not two numbers from one fitted distribution and should not be treated as such. Different protocols, such as a seated test with the elbow bent, produce different values.
Worked example
Example: a 70 year old man with a best grip of 30 kg
Defaults: metric units, male, 70 years old, the non-Hispanic White reference group and a best reading of 30 kg.
- The NHANES tenth percentile for a 70 year old non-Hispanic White man is 32.0 kg.
- Difference: 30 - 32.0 = -2.0 kg, so the reading is 2.0 kg below that reference value.
- The age band mean for men aged 70 to 80 is 34.6 kg.
- Share of the mean: 30 / 34.6 x 100 = 86.7%.
- The tool shows 32.0 kg at age 70, -2.0 kg, 34.6 kg and 86.7%.
Reference table
| Age band | Men mean | Men tenth percentile | Women mean | Women tenth percentile |
|---|---|---|---|---|
| 30 to 39 | 49.9 kg | 42.8 kg | 31.6 kg | 26.9 kg |
| 40 to 49 | 47.8 kg | 41.1 kg | 31.0 kg | 26.2 kg |
| 50 to 59 | 44.0 kg | 38.0 kg | 28.9 kg | 25.0 kg |
| 60 to 69 | 40.8 kg | 35.2 kg | 26.6 kg | 23.2 kg |
| 70 to 80 | 34.6 kg | 32.0 kg | 22.0 kg | 20.0 kg |
Limits
- Compares one reading with population values, and a single measurement is not a diagnosis.
- Uses the dominant hand best of three, which is not the same as the combined two hand value.
- The reference percentiles are published for ten year age steps, so the tool uses the nearest one.
- Applies to adults measured with the NHANES protocol, so a seated test with a bent elbow is not comparable.
Common mistakes
- Using the average of three tries instead of the best one, which understates the value.
- Comparing a combined two hand score with the single hand reference values.
- Measuring with the elbow bent while sitting and then comparing with standing reference values.
- Reading a low result as a diagnosis, when arthritis, nerve problems and medication all lower it.
- Comparing a reading taken on a different day, since grip strength varies with sleep, hydration and effort.
Try it yourself
Quick checks. Answers sit tucked under each question.
A 30 year old non-Hispanic Black man records 45 kg. How does that compare?
The tenth percentile for that group at age 30 is 42.3 kg, so the reading is 2.7 kg above it, and the age band mean is 49.9 kg, so it is 90.2% of the mean.
A 35 year old woman records 21 kg. What does the reference say?
The nearest published age is 30, where the tenth percentile for non-Hispanic White women is 26.9 kg, so the reading is 5.9 kg below it, and 66.5% of the age band mean of 31.6 kg.
How is a grip strength test done on the survey?
Standing, feet hip width apart, arm at the side with the elbow straight and the wrist neutral, the dynamometer adjusted to the hand, three tries per hand with 60 seconds between repeats of the same hand, and the best result for each hand is kept.
Questions
What is a good grip strength?
It depends on age, sex and body size, which is exactly why the comparison has to be against a reference group rather than a single number. For a 70 year old man the mean is about 35 kg.
How do I measure it at home?
With a hand dynamometer, following the survey protocol: three tries per hand, the best result kept, arm straight at the side, and the squeeze made while breathing out.
What does a low grip strength mean?
It is a flag worth mentioning to a clinician, not a diagnosis on its own. Muscle loss with age, arthritis, shoulder problems, nerve compression and some medicines all reduce it.
Is grip strength a test for sarcopenia?
It is one of the measures used in screening for it, together with gait speed and muscle mass. A low value on its own is not enough to make the diagnosis.
Why do the reference values differ between studies?
Because the protocols differ: seated or standing, elbow bent or straight, one hand or both, best or average, and hydraulic or spring dynamometers. The international review in the sources harmonised all of that, which is why its numbers are not the same as the NHANES ones.
How much does grip strength vary day to day?
Enough to matter. Sleep, hydration, caffeine, pain and effort all move the number, so a single low reading is a poor basis for a decision.
Sources
- CDC NHANES: muscle strength and handgrip measurement protocol
- NHANES handgrip reference percentiles by age, sex and ethnicity, in PubMed Central
- Handgrip strength reference values for older adults, in PubMed Central