The Best Body Composition Apps in 2026: Ranked and Reviewed
Your bathroom scales can tell you what you weigh, but they cannot tell you what that weight is made of. Two people at the same weight can look completely different depending on how much of that weight is muscle, fat, or water. That is why body composition matters far more than a single number on a scale — and why a growing number of apps now aim to help you track it.
But not all body composition apps are created equal. Some use AI and your phone camera. Others rely on connected hardware like smart scales or clinical scanners. A few approach it indirectly through nutrition logging or workout tracking. The right choice depends on what you actually want to measure, how much you want to spend, and how much friction you are willing to tolerate.
For this guide, we evaluated the leading best body composition app options across six criteria: accuracy of body composition data, ease of use, cost, hardware requirements, tracking features, and suitability for different fitness goals. Whether you are trying to lose fat, build muscle, or track a GLP-1 transformation, there is an app here that fits. Here is how they rank.
1. SKOR — Best for Visual Body Composition Tracking
SKOR takes a fundamentally different approach to body composition tracking. Instead of asking you to step on a scale or enter manual measurements, it uses your phone camera and AI to analyse your face and body, producing a Body SKOR that reflects visible changes in muscle tone, posture, symmetry, and overall body composition.
The process takes roughly 30 seconds. You take a photo, and the AI scores what it sees. Over time, your Body SKOR trends upward or downward as your physique changes — giving you a clear, objective measure of progress that a mirror alone cannot provide.
It is worth being honest about what SKOR does and does not do. It scores visible physique change: muscle definition becoming more apparent, fat distribution shifting, posture improving. It is not a DEXA scanner and does not claim to measure absolute body fat percentage to clinical precision. What it does exceptionally well is track relative change over time, which is what most people actually need when they are training or losing weight.
Pros
- Camera-based — no tape measure, no scale, no hardware purchase
- AI scoring provides an objective, repeatable metric
- Tracks muscle tone, symmetry, posture, and body contour
- Takes 30 seconds per scan
- Free scans available
- Excellent for tracking GLP-1 transformations and recomposition
Cons
- Scores visible change, not absolute body fat percentage
- Results can vary with lighting and photo angle if not consistent
- Currently iOS only
Pricing: Free scans available. Premium features via subscription.
Best for: Anyone who wants a quick, hardware-free way to track visible body composition changes — especially useful during fat loss, muscle building, or GLP-1 treatment.
2. Withings Body Scan — Best Smart Scale for Body Composition
The Withings Body Scan is the most advanced consumer smart scale available. It uses bioelectrical impedance analysis (BIA) to estimate body fat percentage, muscle mass, bone mass, and water percentage. The scale sends a small electrical current through your body and measures resistance to estimate the composition of different tissue types.
The companion Withings app presents this data beautifully, with trend charts and health insights. It also measures segmental body composition, breaking down fat and muscle estimates for each limb and your torso individually — a feature previously only found in clinical-grade devices.
The main barrier is cost and commitment. The Body Scan retails at around £350, and you need to physically step on it each time you want a reading. BIA accuracy is also affected by hydration, recent meals, and time of day, so readings can fluctuate more than you might expect.
Pros
- Segmental body composition (per-limb breakdown)
- Tracks body fat, muscle mass, bone mass, and water percentage
- Excellent app with long-term trend tracking
- Also measures heart rate, ECG, and vascular age
Cons
- Requires purchasing the Body Scan scale (~£350)
- BIA accuracy affected by hydration and meal timing
- Must be at home and barefoot to use
- Does not assess posture, symmetry, or visible muscle tone
Pricing: App is free. Requires Withings Body Scan hardware (~£350) or a cheaper Withings scale with fewer features.
Best for: People who want detailed numerical body composition data at home and are willing to invest in high-quality hardware.
3. MyFitnessPal — Best for Nutrition-Led Body Composition Tracking
MyFitnessPal is the most widely used nutrition tracking app in the world, with a food database of over 14 million items. While it is primarily a calorie and macro tracker, it does include basic body composition features: you can log your weight, body measurements, and estimated body fat percentage over time.
The body composition features are secondary to the nutrition tracking, which is where MyFitnessPal truly excels. If your approach to changing body composition is primarily through diet — controlling calorie intake, hitting protein targets, managing macros — then MyFitnessPal gives you the tools to do that with minimal friction.
However, the body composition tracking itself is manual and basic. You enter your own measurements, and the app does not analyse photos or connect to body composition hardware beyond basic scales. For someone who wants to see how their body is changing, rather than just track the numbers, you will need a complementary tool.
Pros
- Largest food database available (14 million+ items)
- Excellent macro and calorie tracking
- Free tier available with core features
- Barcode scanner for quick food logging
- Widely supported with third-party integrations
Cons
- Body composition features are basic and manual
- No photo analysis or AI scoring
- Premium subscription required for detailed nutrient breakdowns
- Can encourage an overly transactional relationship with food
Pricing: Free tier available. Premium from £15.99/month or £79.99/year.
Best for: People whose primary goal is fat loss through dietary control, and who want to pair nutrition data with a separate body composition tracker.
4. Cronometer — Best for Micronutrient-Aware Body Tracking
Cronometer is often described as the more serious alternative to MyFitnessPal. Where MyFitnessPal focuses on calories and macros, Cronometer tracks over 80 micronutrients — vitamins, minerals, amino acids — giving you a far more granular picture of your nutritional intake. It also includes a body measurements section where you can log weight, body fat percentage, waist circumference, and other metrics.
The data quality in Cronometer is generally higher than MyFitnessPal because its food database is curated rather than user-submitted, reducing the inaccuracies that can creep in with crowd-sourced data. For people who care about nutritional completeness alongside body composition, Cronometer is the stronger choice.
Like MyFitnessPal, the body composition features themselves are manual. You are logging numbers, not scanning your body. But the depth of nutritional data makes Cronometer valuable for understanding why your body composition may or may not be changing.
Pros
- Tracks 80+ micronutrients, not just macros
- Curated, accurate food database
- Body measurement logging included
- Free tier with full nutrient tracking
- Integrates with Apple Health and Google Fit
Cons
- Smaller food database than MyFitnessPal
- Body composition tracking is manual and basic
- No visual or AI-based body analysis
- Interface is less polished than competitors
Pricing: Free tier available. Gold subscription from £7.99/month or £49.99/year.
Best for: Health-conscious individuals who want deep nutritional insight alongside basic body measurement tracking.
5. Strong / Hevy — Best for Strength-Based Composition Tracking
Strong and Hevy are workout tracking apps designed for people who lift weights. They do not directly measure body composition, but they serve as a powerful proxy: if your lifts are going up while your body weight is stable or dropping, you are almost certainly building muscle and losing fat. Progressive overload data is one of the most reliable indirect indicators of positive body composition change.
Both apps let you log exercises, sets, reps, and weight, then track your progress with charts and personal records. Hevy adds a social element with a community feed, while Strong is more minimalist and focused. Neither app will tell you your body fat percentage, but both give you hard evidence that your body composition is moving in the right direction.
For people who train regularly, pairing one of these apps with a visual tracker like SKOR or a nutrition app like Cronometer creates a comprehensive picture: you can see your strength increasing, your nutrition dialled in, and your physique visibly changing.
Pros
- Excellent workout logging and progressive overload tracking
- Strength gains serve as an indirect body composition indicator
- Clean, intuitive interfaces
- Free tiers available for both apps
- Hevy includes social features and community
Cons
- No direct body composition measurement
- No photo analysis, body scanning, or BIA
- Only useful if you are actively strength training
- Premium required for unlimited workout history (Strong)
Pricing: Both offer free tiers. Strong Pro from £4.99/month. Hevy Pro from £9.99/month.
Best for: Gym-goers who want to track strength progress as a proxy for body composition improvement, ideally paired with a dedicated body composition tool.
6. InBody (App) — Best for Clinical-Grade Body Composition
InBody is the gold standard in bioelectrical impedance body composition analysis. The InBody app pairs with InBody scanners — the large, medical-grade devices you find in gyms, clinics, and physiotherapy practices — to give you highly detailed body composition data including skeletal muscle mass, body fat mass, visceral fat level, and segmental analysis of each limb.
The accuracy of an InBody scanner significantly exceeds that of consumer smart scales. Studies show InBody devices correlate closely with DEXA scans for most metrics, making them the most accurate non-clinical option available. The app stores your scan history, shows trend data, and provides clear visualisations of where you are gaining or losing mass.
The obvious limitation is access. You need to be near an InBody scanner, and scans typically cost £15–£30 each unless your gym includes them for free. You cannot scan at home on your own schedule, which makes frequent tracking impractical for most people.
Pros
- Clinical-grade accuracy, close to DEXA
- Detailed segmental body composition analysis
- Tracks skeletal muscle mass, body fat mass, visceral fat
- Clear visualisations and trend tracking in the app
Cons
- Requires access to an InBody scanner (gym, clinic, or purchased)
- Scans cost £15–£30 each at most locations
- Cannot scan at home or on your own schedule
- Home InBody devices (H20N) cost £300+ and are less accurate than the full scanners
Pricing: App is free. InBody scans typically £15–£30 per session. Home device (H20N) from ~£300.
Best for: Serious athletes or anyone with regular access to an InBody scanner who wants the most accurate body composition data available outside a clinical setting.
How to Choose the Right Body Composition App for You
The best body composition app depends entirely on your goal. There is no single best option for everyone. Here is a simple decision framework based on the four most common goals.
If your goal is to lose fat
Start with nutrition tracking. MyFitnessPal or Cronometer will help you control your calorie intake and hit your protein targets. Pair this with SKOR for visual progress tracking — the combination of dietary data and visible body change creates a powerful feedback loop that keeps you motivated when the scale is not moving.
If your goal is to build muscle
Strength tracking is essential. Use Strong or Hevy to log your workouts and track progressive overload. Add SKOR to score visible changes in muscle tone, symmetry, and overall body contour. If you have access to an InBody scanner, monthly scans can confirm that your muscle mass is genuinely increasing.
If you are on a GLP-1 medication (Mounjaro, Wegovy, Ozempic)
GLP-1 treatments produce rapid body composition changes that the scales capture poorly. You might lose significant fat while retaining muscle, but the scale just shows a number going down. SKOR is particularly useful here because it tracks the visible transformation — face changes, body contour shifts, improved definition — giving you evidence of what the medication is actually doing beyond weight loss.
If your goal is general health
A Withings Body Scan scale gives you the broadest set of health metrics in a single device: body composition, heart rate, ECG, and vascular age. Pair it with Cronometer for nutritional completeness. For periodic check-ins on visible progress, add SKOR. This three-app stack covers nutrition, health metrics, and visual tracking without requiring a gym or clinic.
If you want to start tracking body composition today with zero hardware and zero cost, SKOR is the fastest path. Download it, take a photo, and get your first Body SKOR in under 30 seconds. You can always add nutrition or strength tracking apps later.
Can an App Actually Track Body Composition Accurately?
This is the question everyone asks, and the honest answer is: it depends on what you mean by "accurately" and what you actually need.
Let us break down the main methods and what each can realistically tell you.
DEXA Scanning (the clinical gold standard)
DEXA (dual-energy X-ray absorptiometry) is the most accurate way to measure body fat percentage, lean mass, and bone density. It is used in research settings and is considered the benchmark. However, DEXA scans cost £100–£200 per session, require a clinic visit, and involve low-level radiation. They are excellent for occasional baseline measurements but impractical for regular tracking.
Bioelectrical Impedance Analysis (BIA)
This is what smart scales and InBody scanners use. A small electrical current passes through your body, and the device estimates composition based on how quickly the signal travels through different tissue types. Clinical-grade BIA (InBody) is reasonably accurate. Consumer smart scales are less so — they can be influenced by hydration, meals, and even the temperature of your feet. BIA is best used for tracking trends rather than trusting any single reading.
Visual AI Analysis
Apps like SKOR use AI to analyse photos of your body and score visible changes. This approach cannot provide an absolute body fat percentage, but it excels at measuring relative change — are you visibly leaner, more muscular, more symmetrical than you were last month? For most people, this is actually the more useful question. The advantage is zero hardware, zero cost, and the ability to scan anywhere in 30 seconds.
Manual Measurements
Apps like MyFitnessPal and Cronometer let you log tape measurements (waist, hips, arms, etc.) and use formulas to estimate body fat. This method is free but depends entirely on consistent measurement technique. Small differences in tape placement can produce meaningfully different results, making it the least reliable method for detecting subtle changes.
The bottom line: no app replaces a DEXA scan for absolute accuracy. But for practical, regular tracking of body composition trends, the apps in this guide each offer genuine value — and most people will benefit far more from consistent weekly tracking with any of these tools than from an occasional DEXA scan twice a year.
Frequently Asked Questions
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No app matches DEXA accuracy for absolute body fat measurement. For camera-based tracking, SKOR provides consistent relative measurements of visible body changes over time. For absolute numbers, InBody paired with its clinical-grade scanner is the most accurate app-based option, though it requires purchasing or accessing dedicated hardware. Most people benefit more from consistent tracking of trends than from a single precise measurement.
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Yes, your phone can track body composition using camera-based AI analysis (like SKOR) or by logging manual measurements in apps like MyFitnessPal or Cronometer. Phone-based tracking will not be as precise as clinical tools like DEXA scanners, but it is highly useful for tracking trends and visible changes over weeks and months. The convenience of scanning from your phone also means you are far more likely to track consistently.
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SKOR offers free scans to track visible body composition changes including muscle tone, symmetry, and body contour. MyFitnessPal has a free tier with basic body measurement logging and calorie tracking. Cronometer's free version includes body tracking alongside its detailed micronutrient database. The best free option depends on whether you want visual AI tracking, nutrition-focused logging, or manual measurement recording.
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Body composition apps use various methods depending on their approach. AI photo analysis apps like SKOR use machine learning to score visible changes in muscle tone, body contour, and fat distribution from your photos. Smart scale apps use bioelectrical impedance analysis (BIA), sending a small electrical current through your body via a connected scale to estimate fat, muscle, and water percentages. Nutrition apps use your dietary data to project body composition changes over time. Manual measurement apps let you log tape measurements and use established formulas to estimate body fat percentage.
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Yes, SKOR uses AI to analyse photos and score visible body composition changes including muscle tone, body contour, and symmetry. It works directly from your phone camera without any additional hardware, taking approximately 30 seconds per scan. The app produces a Body SKOR that tracks how your physique is changing over time, making it easy to see progress that might not be visible day to day.
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For visual body composition tracking, SKOR is significantly better than MyFitnessPal — it uses AI to score visible changes in your physique rather than relying on manual measurements. For scale-based data, Withings Body Scan provides far more detailed body composition metrics. MyFitnessPal excels at nutrition tracking with its massive food database, but its body composition features are basic and limited to manual logging. Many people find the best results by pairing MyFitnessPal for nutrition with SKOR for visual tracking.
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Weekly tracking is ideal for most people. Daily scans can show misleading fluctuations caused by water retention, food intake, and lighting differences. Monthly is too infrequent to spot trends or make timely adjustments to your training and nutrition. Weekly tracking gives you enough data points to see genuine trends while smoothing out day-to-day noise. Try to scan at the same time of day and in similar conditions for the most consistent results.
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AI can estimate relative changes in body fat and muscle definition from photos, but it cannot provide the absolute body fat percentage that clinical tools like DEXA scanners can. AI-based apps like SKOR are best used for tracking progress over time rather than obtaining a single precise number. The advantage of AI is consistency and convenience — you can track weekly with no hardware, and the AI scoring removes the subjectivity of looking in the mirror and trying to judge your own progress.
