DEXA vs InBody: Choosing the Right Body Composition Scan

7 MIN READ • BY The BodySpec Team • Jun 17, 2025

An illustration split in half, comparing an abstract body shape with a rising line graph inside it, to a cross-section illustration of the human muscular and skeletal systems.

DEXA vs InBody: Which Body Composition Scan Is Right For You?

TL;DR

If you want gold-standard accuracy, visceral-fat numbers, and bone-density trends, choose a DEXA scan. If you mainly need a quick, radiation-free check-in to watch weekly trends, an InBody scan can do the job—just control your hydration each time.

Quick-Compare Snapshot

Metric	DEXA Scan	InBody Scan
Technology	Low-dose dual-energy X-ray absorptiometry	Multi-frequency bio-electrical impedance analysis (BIA)
Typical Error Margin	±1–2 % body-fat (METS Performance)	±3–5 % body-fat (METS Performance)
Scan Time	10–15 minutes (scan time)	45–60 seconds standing on device
Radiation	~5 µSv ≈ 4 bananas worth (BodySpec)	None
Typical Price	Starts at $40 at BodySpec (view packages)	$10–$40 at many gyms
Key Extras	Visceral-fat, bone-density & segmental analysis	Segmental muscle-mass map

Choosing between a DEXA scan and an InBody test comes down to a simple question: which technology best fits your goals, budget, and need for accuracy? This guide walks you through the science, trade-offs, and real-world examples so you can confidently choose the best test for your specific needs.

How Each Technology Measures Your Body

DEXA: Low-Dose X-Rays Separate Bone, Muscle & Fat

A DEXA scanner emits two X-ray beams at different energies. Dense tissue (bone) absorbs more energy; soft tissue (fat and lean mass) less. Software converts that into a 3-compartment model—fat mass, lean mass, and bone mineral content.

A diagram illustrating how a DEXA beam is absorbed differently by simple iconic representations of bone, muscle, and fat tissue. Bone is represented by a gray bone icon in a box on the left, muscle by a green box in the center, and fat by an orange box on the right. A yellow beam passes from left to right, appearing lighter as it passes through each box.

The scan also maps visceral fat and provides a bone-density score.

Why it matters: Hydration or recent meals have minimal impact on the results, so repeat scans typically vary by <1 % in research settings (Journal of Exercise & Nutrition).

InBody: Bio-Electrical Impedance Estimates Tissue by Conductivity

During an InBody scan, you stand barefoot on the device while holding hand electrodes. A painless multi-frequency current travels through the body.

Illustration showing how an InBody scan works by sending a harmless electrical current through the body to measure composition.

Because water-rich lean tissue conducts electricity better than fat, the device first estimates total body water, then uses proprietary equations to back-calculate fat-free mass and fat mass.

Why it matters: Hydration level, meal timing, and temporary muscle swelling after exercise can shift readings by several percentage points, but the speed and absence of radiation make InBody a popular gym “weigh-in.”

Accuracy & Reliability: What the Studies Show

Measurement	DEXA (Gold Standard)	InBody 770/570/270
Group-level body-fat error	±1–2 %	±3–5 %
Test–retest coefficient of variation	<1 %	1–3 %
Hydration sensitivity	Minimal	Up to 3 % BF swing per 1 % body-water change

Illustrations comparing the accuracy of DEXA and InBody scans. A target with tightly clustered darts represents the precision of DEXA, while a target with scattered darts represents the variability of InBody.

Bottom line: DEXA wins on consistency, while InBody works best as a convenient trend tracker.

Pros & Cons at a Glance

DEXA

Pros

Gold-standard accuracy (±1–2 % BF)
Tracks regional muscle & fat plus visceral fat
Includes non-diagnostic bone-density insight
Low radiation—less than a cross-country flight

Cons

Requires lying still 7–10 minutes
Slightly higher cost & appointment scheduling

InBody

Pros

Lightning-fast (under a minute)
Zero radiation
Widely available in gyms and offices
Easy to repeat weekly for trends

Cons

±3–5 % error and highly hydration-sensitive
No bone or visceral-fat data
Results vary by device model and firmware

Real-World Scenarios: Choosing the Right Scan

1. Emily, 29 – Marathoner Chasing Personal Records

Emily likes weekly feedback. She steps on her gym’s InBody to ensure weight-loss phases don’t cost her muscle, then books a BodySpec DEXA every quarter to confirm the overall picture before adjusting her nutrition plan.

2. Coach Carlos, 38 – Strength & Conditioning Specialist

Carlos oversees 40 athletes. Quarterly DEXA scans provide hard numbers on lean-mass changes and flag creeping visceral fat in linemen. An in-house InBody provides quick progress checks between training phases.

3. Helen, 54 – Tracking Bone Health Trends

Helen’s doctor orders diagnostic DEXAs every two years for osteopenia. Between those medical scans, Helen books non-diagnostic BodySpec whole-body DEXAs quarterly. These track bone-density trends plus body-fat changes, helping her fine-tune diet and strength training.

Decision Tree: Pick Your Best-Fit Scan

An icon-based comparison showing DEXA's strengths like analyzing bone density and visceral fat accurately, versus InBody's strengths which include faster and more frequent scanning.

Need bone-density metrics or visceral-fat data?
- Yes → Choose DEXA
- No → Next question
Is ±3–5 % error acceptable for your goals?
- Yes → InBody suits rapid, frequent check-ins
- No → DEXA gives tighter accuracy
How often will you test?
- Weekly/bi-weekly → Use InBody regularly and add a periodic DEXA baseline
- Monthly/quarterly → DEXA alone is sufficient

Cost, Convenience & Safety Considerations

Price: BodySpec scans start at $40—see packages. InBody sessions usually run $10–$40.
Time: Plan on about 15-20 minutes total for a DEXA visit (setup + scan + review) versus ~5 minutes for InBody.
Radiation: Whole-body DEXA ≈ 5 µSv—less than a cross-country flight or eating four bananas (BodySpec).
Prep: Hydration barely affects DEXA, but a 1 % body-water shift can swing InBody BF % by up to 3 % (Journal of Exercise & Nutrition). Consistency is king for both scans—use the BodySpec prep checklist (morning, fasted, similar clothes) as a universal protocol.

Frequently Asked Questions

Is a DEXA scan safe?

Visual comparison illustrating that the amount of radiation from a DEXA scan is equivalent to the radiation from eating four bananas or taking a cross-country flight.

Yes. A whole-body DEXA exposes you to roughly 5 µSv—less radiation than a cross-country flight and about the same as eating four bananas (BodySpec).

How often should I get a DEXA?

Most BodySpec clients scan monthly or quarterly to guide training blocks. Follow your physician’s advice for medical monitoring.

How much do hydration or meals impact InBody accuracy?

Illustration showing a body with water in the lower half, with an arrow pointing to a box with "BODY FAT %" and a wavy line indicating fluctuating body fat percentage readings.

Up to a 3 % body-fat change per 1 % body-water shift (Journal of Exercise & Nutrition). Always replicate hydration, meal timing, and exercise state.

Does DEXA measure visceral fat directly?

Diagram showing magnified layers of fat within a human silhouette.

It provides a clinically validated estimate. The scanner analyzes the android (waist) region to quantify visceral adipose tissue (VAT), delivering a research-grade visceral-fat number that InBody cannot match.

Can InBody track small muscle gains?

It tracks trends, but small month-to-month changes may hide in the ±3–5 % noise. Use DEXA periodically for confirmation.

The Bottom Line

If you need ultimate accuracy, visceral-fat scores, or bone insights, DEXA is the gold standard. For quick, radiation-free checkpoints between workouts, InBody is a handy sidekick—just keep hydration consistent.

Ready to see your numbers? Book your BodySpec DEXA scan today.