How To Estimate Your Body Fat Percentage
Body Fat percentage is quite literally the percentage of your mass that is made up by fat.
If you weigh 200 lbs at 10% body fat, you will have 20 lbs of fat on your body and the rest (180 lbs) will be lean mass – muscle, bone, skin, organs etc. and some water.
Weigh 200 lbs at 30% body fat and you have considerably less lean mass and considerably more fat mass. Your fat mass would be 60 lbs and your lean mass would be 140 lbs.
So, how do you know what your body fat percentage is?
It can be quite difficult to get an accurate idea of your body fat percentage.
Let me start by saying that the scales in your bathroom are absolutely wrong. I don’t care how much they cost, they’re wrong.
At the time of writing, I am around 13-15% body fat (the mirror and my experienced eye tell me this) but my scales put me at 23%.
There are a few ways of assessing your body fat percentage, but they all have their problems.
The only way to get a truly accurate measure of your body fat percentage is to get a DEXA scan. It involves going in to a medical facility for an appointment. You lay on a padded mattress in a gown or in your underwear while a scanning arm passes over your body. It uses a low dose of X-Ray to give an accurate measure of lean mass, fat mass and bone mass.
As most of us don’t have access to DEXA scanning equipment, you have to pay for a private appointment, and it isn’t cheap.
But there’s no real need to actually have a DEXA scan.
Why Do You Need to Know Your Body Fat Percentage?
Say you get a DEXA scan and it tells you that you’re are 16% body fat. You go “ok, I thought I was somewhere between 15-20%, so I guess that’s cool.”
What’s the point? Why do you need to know the precise number? So you can brag about being single digit body fat? It’s not going to change whether you continue losing fat or not. That is based on whether you like what you see in the mirror. If the DEXA scan tells you you’re 12% bodyfat but you think you can get leaner and you’d like to, then why not continue?
One reason people might think they need to know their exact body fat percentage is so they can enter it into calorie calculators to work out how much they should be eating – but you really don’t need to be that exact about these things. Ballparks, estimations and then adjusting course depending on progress will get you there if you’re tracking calories.
Another reason you might want to know your exact body fat percentage is because you’re not seeing any changes on the scale, but you’re sure you’re looking better in the mirror, feeling stronger and your clothes are fitting better. You’re wondering if you’re losing fat and building muscle at the same time. This would explain why you’re not really seeing progress on the scale. This is a legitimate reason to want to know your body fat percentage, but you don’t need to get a DEXA scan to confirm it. It’s just too expensive and inconvenient.
In this case, you can do one of these things instead to confirm your beliefs:
- Take pictures weekly and compare them. Note your weight on each picture. Don’t just compare week to week – muscle takes a long time to build – so compare to several weeks/months before as well. Looking more muscular now than you used to but the scale is staying the same? Then you have more muscle at the same weight – in which case your body fat percentage HAS to have come down.
- Use another method to estimate your body fat percentage, and just accept that it is not 100% accurate.
- Skinfold test using calipers: These are pinchy (usually plastic) things that you use to “grab” your fat and measure how thick it is. They’re very cheap. You can order some on Amazon (UK link, US link).
- Body fat percentage reading on scale: This is likely to be very inaccurate. It will give you a completely wrong number BUT it should be consistently wrong. By that, I mean that it should always be out by the same degree. So whilst the actual figure is wrong, the trend should be correct. If it shows your body fat percentage trending down, then that is likely to be accurate. Combine this with a visual test using pictures to confirm your beliefs.
- Compare to pictures of other people: Your visual test (comparing pictures of yourself) may show that you’re obviously lowering your body fat percentage, but it doesn’t give you a clue of what that body fat percentage actually is. You could be thinking “great, I look better than 6 weeks ago”, but you still have no idea what number to put into the calorie calculator to calculate your maintenance calories. You can get a very good ballpark by simply comparing how you look to pictures of other people.
Example Body fat Percentages for Men and Women
The pictures below show you what various different body fat percentages will look like.
A key thing to note is that a woman at the same body fat percentage as a man will look considerably leaner. This is because women have higher levels of essential fat than men.
Amount of Muscle Mass Makes A Big Difference to Appearance
The first four men in the above examples and the first three women (perhaps four) are athletes.
Muscle mass makes a difference to how you look at different body fat percentages.
A man at 10% body fat with decent levels of muscle mass (has trained seriously for at least 2 years) is going to look seriously more impressive, “shredded” and “jacked” than a man at 10% body fat who has never trained.
Another thing that affects how lean someone looks, is the level of ab development they have.
Your abs are a muscle that can grow. The more you work and develop them, the stronger they show through at different levels of body fat.
Someone who doesn’t train abs often at all, may not really have them visible at 15% body fat, whereas someone who has trained abs a lot may be able to see them quite well. Visibility of abs has become a barometer for leanness, with people assuming that the more visible your abs are, the lower your body fat percentage must be.
Sometimes people think they must be 10% body fat because they can see their abs, then they get a DEXA scan and are bemused by a result of 13, 14 even 15% body fat!
If you have less developed abs, you will have to get leaner before you can see them.
Body fat distribution also impacts on body fat percentage!
As just established, visibility of abs is generally how people assess someone’s leanness. Another thing that makes abs more visible at higher than usual body fat percentages is where an individual stores their body fat.
Some lucky people store fat in other areas before they start storing it on their abdomen! People who store more fat on their quads, glutes, arms, face etc. will have less fat obscuring their abs. We’re talking about fine margins at body fat percentages below 15-18% here – not drastic differences at higher body fat levels. People aren’t walking around with six packs and flabby legs. But people ARE walking around with six packs and slightly less shredded legs and glutes, and slightly less chiselled jaw-lines.
If you’re one of the lucky people who doesn’t store as much fat on their abdomen, you’ll be able to see your abs at higher body fat percentages than the average person. – again, maybe even at 15% body fat
Be Aware that Physique Shots are Staged
Photos of fitness models and photos posted by fitness influencers on social media are prepared.
These people may have tans (real or fake) – making them look leaner. They will also be taking the picture under the perfect downward lighting – which will highlight all of their definition. Add to this that they’ve probably JUST worked out, so all of the muscles (which are already very defined and visible at low body fat percentages) are popping and vascular – making them look leaner still. Abs are of course being squeezed as hard as possible.
At low body fat levels, what you’ve eaten and drank within the last couple of days makes a huge difference to how lean you look too, as it affects how much water is retained beneath the skin. Retaining water INSIDE muscles is good. It makes them look full and pumped. Too much, however, and that water will be retained outside of the muscles, under the skin. This will make your muscles look more obscured and the individual less lean. A really high carb meal can cause this.
People get all of the above right and then post it on Instagram with the caption “10% body fat!”. This NOT going to be comparable to how you look in the mirror the morning after a cheat day, with your main bedroom light on, before you’ve trained and looking like you haven’t seen the sun in your lifetime. You MAY actually be a similar body fat percentage to the picture you’ve seen, but you’re not comparing like for like.
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