Weight loss is a big industry – the majority of my own personal training clients have been looking to lose body fat, slimming down into a healthier, more comfortable version of themselves.
Therefore, any device promising to help with fat loss stands a good chance of being incredibly useful or catching on and engaging the public’s imagination – and sometimes, when we’re lucky, doing both.
Body fat scales are definitely in the latter camp. They have caught on, thanks in large part to weight-loss TV shows, in part to good advertising, in part to the chunky machines in the corner of many modern gyms’ changing rooms, and in part due to the promise they give you.
They can measure your body fat and tell you how that diet is doing.
But what exactly are they? Do they work? And what model, if any, should you invest in?
Let’s begin in our quest to find the best body fat scales.
What Are Body Composition Scales?
I want to begin this discussion as frankly as possible with you.
Body fat scales are not very accurate. They are designed to estimate a person’s body fat percentage, though they often claim to be able to fully gauge it. Take this lesson to heart – they can only estimate, and sometimes they don’t even do that particularly well. I don’t really like them all that much.
However, I also recommend that you consider buying one if you’re on a weight loss journey.
Their accuracy isn’t really the point. Their relative accuracy is. They can tell you pretty certainly whether you are losing or gaining fat, which is a big deal. They also work well in tandem with BMI calculations in non-athletic individuals, giving a rough idea of how much fat that person has, and giving a good indication of their overall health and body composition.
Body fat scales can do this at home. From the comfort of their own bathroom, somebody can measure their weight and body composition (the relative percentages of fat, muscle, and water in their body’s makeup).
Understanding this composition is vital in weight loss – the key to any good weight loss routine is the loss of bodyfat and the retention of muscle, meaning that weight alone is an imperfect guide.
Body fat scales are not accurate, and I’m going to labour this point a lot. They also don’t show fat distribution – they don’t tell you how your fat is stored. This is important. Body fat location is key in estimating somebody’s susceptibility to disease. There is a correlation, for example, between abdominal fat and somebody’s risk of suffering from cardiovascular disease.
However, as above, relative accuracy and ballpark estimates are still worthwhile data in any weight loss journey.
The main advantage to using body fat scales at home is convenience. There are better, more accurate ways to measure body fat, such as hydrostatic testing and MRI scans. However, these involve expensive equipment run by professional experts – a degree of laboratory access, in other words, that most of us don’t have access to.
Body fat scales are rough and ready, but they work to a point, they are accessible, and they are convenient.
How Do Body Fat Scales Work?
Body fat scales use bioelectrical impedance analysis (BIA.)
BIA involves sending a weak electrical impulse through the body. This pulse encounters varying levels of resistance, or impedance, from different tissues and substances that make up your body. Fat offers more impedance than either muscle or water – higher resistance values, measured in time taken for the impulse to pass, show us higher levels of body fat.
This allows body fat scales to estimate the relative percentages of different tissues and substances within the body, including bone, water, muscle, and, of course, fat, using a mathematical formula that incorporates the value for electrical resistance with information about a person’s age, height, and gender.
This can tell you the relative percentages of total fat, muscle, water and bone density in your body.
Though rough in outcome, it’s all really quite clever!
Body Fat Scales: Our Top Picks
So, if you are wanting to lose or gain body fat, and you have decided that getting a rough but regular reading is going to be helpful to you (hint: it usually will be), then you will probably want to invest in a set of body fat scales.
This list contains some of the best models going, all with relatively good degrees of accuracy, most with smart features that sync to apps and so on. They all bring something special to the table and are all very reasonably priced for what they do.
FitTrack Dara Scales
I’m not sure where they get their numbers from, but FitTrack claim you can reach your weight loss goals up to eight times faster using their Dara scales.
This may or may not be true – it’s hard to quantify or generalise, and everybody will have a different experience, so I suspect not. However, the point still stands. You will likely be able to hit your goals more ably, more efficiently and, ultimately, more expediently using their scales, as you would with many brands’ body fat scales.
There are a few things that FitTrack’s Dara scales have going for them that may give you the edge compared to going with many more standard models. You can measure far more than simply your body fat percentage. There are no fewer than 17 different vital body health metrics. There is an ‘Active Mode’ for more active users, alongside accurate, body type reporting. This means that you will be able to get the best estimates for your body type, which is a huge deal.
FitTrack also claim that theirs is the most accurate body composition scale in its class, at +/- 3% as accurate as a medical DEXA (x-ray) body fat percentage scan. If this is true, and I have reason to suspect that it isn’t, then this undermines my main criticism of body fat scales. This level of accuracy makes them a potent training tool.
Part of this is due to their incredibly smart algorithm adjustments, all based on individual habits. As it’s the equation that usually lets these kinds of machines down, this is, again, a big deal – it will account for the FitTrack’s purported accuracy and will go a long way to backing it up.
It’s also family friendly. You can create 8 different profiles, so that everyone in your household can use it with their own customisations, and there are even options for use on infants.
FitTrack’s Dara scales are a truly impressive first offering on this list.
Renpho Body Fat Scales
Renpho’s Body Fat Scales are the first on this list with really impressive app capability.
The scales take 13 measurements, including BMI, muscle mass, and body fat percentage, and stores it all on the Renpho app. It syncs with multiple devices seamlessly, and millions of users are already plugged into it. If you weigh yourself without your phone, the data will sync to the app once connection is re-established.
It’s not the most impressive app technology I’ve seen, but it doesn’t need to be. It’s well thought out, well programmed, and incredibly useful.
The scales themselves are relatively accurate. Auto calibration and high precision sensors mean that they are very sensitive – they measure in increments of 0.2lb/0.05kg, up to 180kg (which should be more than enough for all but the largest of athletes.) There are four sensitive electrodes that take the measurements needed, through a 5mm tempered glass platform.
It’s sleek looking, well designed, and a pleasure to have in the bathroom and to use.
Voxon Body Fat Scales
Voxon’s Body Fat Scales also offer a far greater range of measurements than simple body fat – as pretty much everything on this list will. The data these machines can collect is invaluable, so any that only go with one or two are often not particularly worthwhile. They are not well thought out and they give poor value for money.
In this case, we get 13 different datasets. These include weight, BMI, body fat, fat-free body weight, subcutaneous fat, visceral fat, body water, skeletal and muscle mass… it goes on. You even get your metabolic age (though I really don’t think this is accurate).
There is also a very good app that comes with these scales, in the form of the free Fitdays App, available both from the Play Store or Apple Store, which will sync with Apple Health, Google Fit and Fitbit. You can track your progress seamlessly, storing historical data and keeping tabs on how your fat loss or gain journey is going week by week, month by month, making it far easier to achieve your goals.
The clear LCD digital scales have Step-on Technology, which is a bit nifty, and it includes 4 high precision pressure sensors and advanced auto-calibration function to make sure that all data is reliable. So far, so good… but all a little standard.
The thing that sets Voxon’s offering apart from some of the rest in its category is the sheer number of users it can support – a full 24, with one main user and 23 sub-users. This may sound superfluous – I thought it was at first. Nobody lives in that large a household, surely?
However, this sets up Voxon’s body fat scales perfectly for team and club use. Do you run a karate club, with several members wanting their biometrics tracked? Do you coach a football or rugby team, or run a weight loss group? This is the machine for you.
Salter Ultra Slim Bathroom Scales
Salter market their offering as a set of ‘Ultra Slim Bathroom Scales’. They are chic and elegant; they are indeed slim; and they will look stylish in the corner of the swishest of lavatories. Full marks, here.
However, they have made this list – they are amongst the top contenders in the body fat scale world. Why is that?
Well, they measure your body fat really well, in short.
Salter themselves are one of the top UK brands for bathroom scales. They have pedigree, and then some – Salter Housewares dates back to 1760, and have spent the intervening centuries growing, adapting, innovating and thriving.
They must be doing something right!
They have a well-deserved reputation for precision and accuracy. All of their products are held to this high standard, and all the ones I’ve ever come across play a good game. In fact, Salter themselves are so confident that they back their products with a manufacturer’s guarantee for 15 years.
That’s quite something.
The Ultra Slim Bathroom Scales measure body fat, body water, weight, and BMI. This is hardly exhaustive, but they get the basics in there. They are vibration activated, so that a simple toe tap or step on will get it going, and it gives you an incredibly accurate weight reading. It has four user memories – again, hardly exhaustive, but adequate – so that multiple members of your family will be able to use it and store their long term data.
This is who it’s for – you and your family. There is little use for it in a wider context, unlike some of the machines on this list, but Salter are marketing household products here. And, designed with ultra slim toughened glass and an ‘easy to read’ LCD display, it is indeed a great product for any stylish bathroom, as mentioned above.
It may be as much fashion accessory as utility driven fitness tool, but it does its job well. The Salter Ultra Slim Bathroom Scales knows its lane and sticks to it masterfully.
EtekCity Body Fat Scales
Here we have another smart app. EtekCity’s Body Scales and its app syncs with other fitness apps, like Apple Health, Google Fit and Fitbit, works with Bluetooth 4.0, and supports Android 4.3 & IOS 8.0 or above system.
So far so good. If you’re into your tech and gadgets, and you want reliable, long term data recording and storage, you’re in good hands. The app is easy to use and the connectivity is great. If you weigh in without connectivity, the scales will store your data and automatically sync to your phone at the next opportunity. It is available to all the family, though I’m none too sure on the upper limit for user profile numbers.
These scales measure 13 data points, which is the right side of average for this list. These include what you would expect from this calibre of body fat scales – weight, body fat, BMI, fat-free body weight, subcutaneous and visceral body fat, skeletal and muscle mass, BMR and so forth.
The build itself comes with some impressive specs. It includes 6mm thick tempered glass and weighs in increments of 0.05kg (0.2lb) with a 180kg/28st/400lbs upper weight capacity. This is both robust and precise, which are two adjectives that you’re always pleased to hear connected to a set of high-end scales.
A nice, self-illuminated LED display provides clear readouts at any angle. The model’s rounded corners spare household members from sharp edges (useful with tots tottering about).
The accuracy comes from four high precision sensors and four sensitive electrodes, which makes this model about as accurate as any at-home body fat scales can be (damning with faint praise, perhaps, but still worthwhile).
You get a 2-year warranty from Etekcity and their customer support team has a reputation for stellar knowledge and service.
InSmart Body Fat Scales
The InSmart Body Fat Scales measure thirteen data points, including weight, BMI, body fat, fat-free body weight, visceral and subcutaneous fat, muscle mass and so on. You get a 6mm high quality toughened glass plate that measures in tiny increments – 0.2lb/0.05kg with a 180kg/28st/400lbs maximum user capacity.
InSmart Body Fat Scales also make use of 4 high precision sensors and 4 sensitive electrodes to ensure accuracy, and have a self-illuminated LED display for clear reading.
These scales are also compatible with Bluetooth 4.0 and operating system iOS 8.0/Android 6.0 or higher, and have an app – FITDAYS, in their case – that can be synchronized with Fitbit App, Apple Health, Google Fit & Samsung Health. As with most of the items on this list, you can weigh yourself at any time without your phone – the scales will sync with your device when they are next connected.
Active Era Body Fat Scales
Active Era’s Body Fat Scales measure fifteen data points, putting it slightly above average, though still within a pretty normal range. This includes weight, BMI, body fat, fat-free body weight, visceral and subcutaneous fat, muscle mass, metabolic age, muscle and bone mass, and skeletal muscle percentage.
There is also good device connectivity – they connect with the Apple Health, Google Fit and Fitbit apps so that you can fully, properly track your body composition over time.
One of the main things that sets them apart for me, is the precision of the measuring. Active Era’s Body Fat Scales have eight highly advanced weight and composition sensors with 0.1kg accuracy, which is well above average for this list. Inasmuch as body fat scales can be accurate (we’ve established they struggle with full, real terms accuracy) this is very impressive.
There is a pretty standard weight limit of 28 stone/180kg/400lb, which, again, should be more than enough for even the largest of athletes.
The second thing that really sets Active Era’s Body Fat Scales apart from the competition is the number of user profiles it can support. You get a full forty, making it perfect for families and fitness classes alike. Group fitness leaders, coaches, and personal trainers with a roster of clients will do really well to consider investing in one.
The design is pretty decent, too, with an ultra-strong 6mm tempered glass platform, 4 anti-slip safety pads, and a sleek midnight black finish.
It would look good in any studio.
How Accurate Are Body Composition Scales When Determining Body Fat?
I’ve already covered this in part, but it really is worth going over.
There are some fantastic pieces of equipment out there that will measure fat with a good degree of accuracy. Body composition scales are not one of them.
For example, you can use an air displacement chamber. You will enter a chamber and the displaced air gives results about body fat, water, muscle, and bone. You can use hydrostatic testing, which uses a similar method in a bath of water. MRI scans can be used to measure body fat in a clinic.
However, these are all expensive and take specialist labour. None of them can be performed at home, of course. Many are inappropriate for children and pregnant women.
So, if you want accuracy, there is a trade-off – it will cost you a lot more and give you a lot more inconvenience and may not be safe or appropriate for some groups.
Body fat scales tip to the other side of this trade-off continuum – they are safe, cheap and convenient, but they aren’t very accurate. Studies on them, that show some promising results, are also flawed – the data gathered are collected from an incredibly small population sample.
In fact, many studies show up their inaccuracy in quite a startling way. BIA has been shown to be accurate when using standard, published mathematical formulas. However, this often doesn’t make it to market. Commercial body fat scales used by researchers did not use accurate formulae, nor were their BIA systems particularly efficient.
A 2016 report in Consumer Reports showed that six standard commercially available body fat scales could under- or over- estimate body fat percentage to a very large degree. The most accurate readings were about 21% off, whilst the least were about 34% off.
That’s massive. It’s the difference between somebody being a healthy weight and not.
As above, they also don’t show where somebody’s body fat is stored, which in many cases is a far more important determinant in somebody’s overall health than their total body fat percentage.
They are, in short, seriously flawed machines.
However, they are pretty consistent, in a relative sense. They might be 30% off, but they will be every time. If you want to lose or gain fat, they will tell you how well you are doing, most of the time.
For instance, if they consistently overestimate your fat levels by 30%, but the figure they give you is going downwards, you will know that you are losing body fat. That is extremely useful data.