Body composition scales are really popular right now, and it’s easy to see why. They do more than just measure your weight. They go much deeper, giving you insights into everything from body fat to muscle mass. Whether you’re trying to bulk up or lose weight, you can keep track of your progress far easier than ever before.
But how accurate are they? And do they really help with fitness goals? Let’s weigh in with the facts…
What is a body composition scale?
Body composition scales give you a breakdown of your body’s health. First of all, they send a harmless electrical current through your body (don’t worry, you won’t feel a thing). Based on how different tissues like fat, muscle, and bone resist this electrical current, the scales can estimate lot of different things – such as body fat percentage, muscle mass, and even water retention.
Here are a few of the common measurements you’ll find on a body composition scale:
Body fat percentage (how much of you is made up of fat)
Visceral fat (the fat around your organs)
Muscle mass (how much muscle you’re packing)
Bone mass (the weight of your skeletal system)
Basal metabolic rate (BMR) (the calories your body burns at rest)
Total body water (how hydrated you are)
How do body composition scales work?
So, how do these scales do their measuring? Here’s a simple breakdown of the process:
Electric current. When you step on the scale it sends a tiny, harmless electrical current through your body.
Resistance. Different parts of your body (fat, muscle, bone) resist the current in different ways. Muscle lets the current flow easily, fat offers more resistance.
Maths. The scale gathers its measurements, then factors in things like your age, height, and gender to give you estimates on your body composition.
What’s the difference between a regular weighing scale and a body composition scale?
There are some important differences between a regular weighing scale and a body composition scale. Here’s a comparison table to help:
| Metric | Â Â Â Â ÂRegular scale | Â Â Â Â ÂBody composition scale | Â Â Â
|---|---|---|
| Measures | Â Â Â Â ÂWeight only | Â Â Â Â ÂWeight, body fat %, muscle mass, bone mass etc. | Â Â Â
| Technology | Â Â Â Â ÂLoad cell (measures weight) | Â Â Â Â ÂLoad cell + electrodes (BIA) | Â Â Â
| Price range |     Â£10–£50 |     Â£30–£300 |   Â
| Connectivity | Â Â Â Â ÂNone | Â Â Â Â ÂSyncs with smartphone apps | Â Â Â
| Used for | Â Â Â Â ÂQuick weight check | Â Â Â Â ÂTrend tracking, fitness progress, body composition estimates | Â Â Â
As you can see, while a regular scale only tells you your weight, a body composition scale gives you a more through breakdown of your body. This makes it a useful tool for tracking your fitness over time, rather than just focusing on how much you weigh.
How accurate are body composition scales?
The short answer to this question is - accurate, but not exact. Studies show that body composition scales are fairly close to DEXA scans (the gold standard for body composition analysis), but with a small margin of error – typically about 3-5% for body fat. Also, keep in mind that certain things can affect the accuracy of the readings:
Hydration. If you’re dehydrated, your body fat percentage could appear higher than it is.
Muscle mass. If you’ve got a lot of muscle, the scale might under-report your body fat. This is because muscle conducts electricity better than fat.
Time of day. If you’re weighing yourself after a heavy meal or workout, your results might be different than if you weighed yourself in the morning.
Pro tip: Always weigh yourself first thing in the morning, after using the bathroom. This will give you the most consistent results.
Body composition scales FAQs
Are body composition scales safe?
Yes, body composition scales are safe for most people. The electrical current used is extremely low so you won’t feel a thing. But if you have an implanted pacemaker or defibrillator, you should chat with your doctor before using these type of scales.
Do you need wet feet for body composition scales?
No, you don’t need to have wet feet. This is a bit of a myth. You just need to make good contact with the scale’s electrodes. However - if your feet are too dry, the scale might not give you an accurate reading. To improve contact, lightly wiping your feet with a damp towel or cloth can sometimes help.
How do you read a body composition scale?
Most body composition scales come with an app that displays your body fat percentage, muscle mass, and total weight. When looking at the results, remember that body composition changes slowly over time. Don’t get too hung up on day-to-day fluctuations—look for trends over weeks or months.
To help you understand your body fat percentage, here’s a simple guide based on age and gender (from NHS guidelines):
| Age group | Women | Men |
|---|---|---|
| 20-39 | 21-33% | 8-20% |
| 40-59 | 23-35% | 11-22% |
| 60+ | 24-36% | 13-25% |
How to choose the best body composition scales
Accuracy is the main thing to consider when you’re choosing body composition scales. But you should also think about how easy it is to use, and whether it syncs with other apps you’re familiar with. Also, if you’re sharing the scales with other family members, make sure it has a multi-user mode. Here are two options that are easy to use and give reliable results:
Withings Body+ Smart Body Composition Scale
The Withings Body+ tracks the likes of body fat, muscle mass, bone mass, and water percentage. It syncs over Wi-Fi with the Health Mate app, so you can automatically track your progress. And it supports multiple users, so it’s great for families.
Renpho MorphoScan Smart Body Scale
The Renpho MorphoScan helps you keep track of your health easily. It measures different metrics including body weight, BMI, body fat and muscle mass. It also connects to the Renpho app where you can view progress and set goals. And just like the Withing scale above, it lets different people use it.
Need more help?
If you’d like more advice on choosing the best health and fitness tech, our smart fitness buying guide is a great place to start. If you need more advice on choosing the right digital weighing scales or any other tech, why not pop in-store? Our colleagues are always happy to help.
