What does my body fat percentage mean?
15% is normal at any adult age on the chart. 30% is very high at all ages. 20% is high under 40, normal after. But these aren’t NHS lines, and scales can be well out.
On this page
Is 15% body fat good for a man?
Yes, on the chart a major scale maker gives out with its scales. For men aged 20 to 39, the normal band is 8 to 19.9%. So 13%, 15% and 19% all sit inside it.
15% is also lean next to most men. A large US study measured body fat with a DXA scan, an X-ray scan that sorts fat from muscle and bone.
Only 3.8% of men aged 20 to 39 were under 15%.
- Below 8 %Low on the scale chart.
- 8 to just under 20 %Normal.
- 20 to just under 25 %High.
- 25 % or aboveVery high.
Sources: Akindele 2016 (scale chart); Gallagher 2000
Over 40? The lines move up. Find your age row in the next section.
Is 20% body fat good or bad?
It depends on your age. Under 40, 20% is the first step into the high band. From 40, it’s normal.
| Age | Normal | High from, then very high from |
|---|---|---|
| 20 to 39 | 8 to 19.9% | 20%, then 25% |
| 40 to 59 | 11 to 21.9% | 22%, then 28% |
| 60 to 79 | 13 to 24.9% | 25%, then 30% |
Sources: Akindele 2016 (scale chart); Gallagher 2000
So 19% is normal at any age. 22% is high up to age 59, and normal from 60.
Why do the lines move? In the 2000 study behind them, age, sex and ethnic group all changed how much fat went with a given BMI.
The chart doesn’t say which ethnic group it fits, so treat it as a rough guide. Read your number against your own age row, not one chart for all men.
Is 30% body fat obese?
It’s in the top band, very high, at every age on the chart. That study turned the BMI (your weight measured against your height) lines for overweight (25) and obesity (30) into body fat. The very high band lines up with the obesity line.
But its authors wrote that no accepted ranges existed, and called theirs provisional, meaning a first try, not final. These aren’t NHS lines. The NHS checks your waist and BMI instead.
| Body fat | Men aged 20 to 39 | Men aged 40 to 59 |
|---|---|---|
| Under 15% | 3.8% | 0.4% |
| 15 to under 20% | 15.7% | 5.8% |
| 20 to under 25% | 23.1% | 16.9% |
| 25 to under 30% | 30.3% | 37.4% |
| 30 to under 35% | 17.9% | 27.6% |
| 35 to under 40% | 7.4% | 9.9% |
| 40% or more | 1.9% | 2.0% |
Source: Flegal 2009 (NHANES, DXA)
So 30% is common, and still very high on the chart. Common and healthy aren’t the same thing.
These are US men measured from 1999 to 2004, not UK figures. Reading 30%? Check your waist against your height next.
How accurate is your body fat number?
Less than the decimal point suggests. A study tested a home body fat scale against DXA in 43 overweight or obese men.
On average, the two were 1.2 points apart. But most single readings were only within 9.5 points either side of that.
Think of a class average. The class can score 60 while one pupil gets 50 and another gets 70.
Your scale reading is that one pupil. It can be further out than the whole high band, which is only 5 points across for men under 40.
| Method | How far out | Tested on |
|---|---|---|
| Home body fat scale vs DXA | Most within 9.5 points either way | 43 overweight or obese men, BMI 28 to 43 |
| Body fat worked out from BMI | Typical error 2.8 to 5.4 points | 1,626 adults, BMI up to 35 |
Sources: Pateyjohns 2006; Gallagher 2000
The authors said such scales may help compare groups, but are of limited use for one person.
To track change, use the same scale at the same time of day. Watch the trend over weeks, not one reading. More in body fat scales vs DEXA.
What does the NHS use instead?
Your waist and your BMI. The NHS says to keep your waist to less than half your height. At 180 cm tall, that’s a waist under 90 cm.
BMI can mislead muscly men. The NHS says the BMI calculator cannot tell the difference between muscle and fat. So you may read overweight without much body fat.
If your BMI is under 35, the NHS waist-to-height calculator can show if you carry too much fat round your tummy.
Six ways to read your body fat number
- Read your number against your own age row, not one chart for all men.
- Use the same scale at the same time of day, and watch the trend over weeks.
- Measure your waist. The NHS says to keep it to less than half your height.
- If your BMI is under 35, try the NHS waist-to-height ratio calculator.
- Muscly? Remember the BMI calculator cannot tell muscle from fat.
- These bands come from a scale maker’s chart, not the NHS, and a home scale can be well out.
Sources: NHS; Akindele 2016 (scale chart)
More on each check: waist-to-height ratio vs BMI, what your BMI means and keeping muscle while you lose fat.
When to speak to a GP
The NHS says to see a GP if your BMI is overweight or obese and:
- you want help to lose weight
- your waist is more than half your height
- you have pre-diabetes, diabetes, high blood pressure, joint pain, high cholesterol, sleep apnoea (breathing that stops and starts as you sleep) or heart and circulation disease
- obesity runs in your family
- you have, or think you may have, an eating disorder, such as binge eating
Speak to a GP too if you have a condition that makes it harder to stay a healthy weight. Carry weight round your middle? See visceral fat and blood tests.