What to Use Instead of BMI: 5 Better Alternatives

Last updated: June 2026

BMI (body mass index) divides your weight by your height squared. That’s it. It says nothing about where fat is stored, how much of your weight is muscle versus fat, or whether the fat you do carry is the metabolically harmful visceral kind. These are not minor omissions — they’re the gaps that make BMI a poor predictor of cardiometabolic risk for large categories of people. Here are five alternatives that do what BMI cannot, with the trade-offs of each.

Why BMI Falls Short

Before exploring alternatives, it’s worth understanding exactly what BMI gets wrong:

• It conflates muscle and fat. A muscular athlete with low body fat and high muscle mass may have a BMI of 27 — “overweight” — despite carrying minimal health risk. Meanwhile, someone with average weight but high abdominal fat can have a perfectly normal BMI while carrying elevated cardiovascular risk.
• It ignores fat distribution. Visceral fat (around the internal organs) is far more metabolically harmful than subcutaneous fat (under the skin). BMI cannot distinguish between them.
• It fails across ethnicities. Asian populations face higher risk of diabetes and cardiovascular disease at BMI levels considered “normal” in Caucasian-derived thresholds. BMI’s universal cut-offs were not derived from globally representative populations.
• It misses normal-weight obesity. People with a normal BMI but high abdominal fat and low muscle mass — a pattern called “metabolically obese, normal weight” — are classified as healthy by BMI but carry elevated risk.

A 2016 study published in the International Journal of Obesity found that nearly 47% of individuals classified as “overweight” by BMI were metabolically healthy based on blood pressure, cholesterol, and glucose — while a significant proportion of those with “normal” BMI had unhealthy metabolic profiles. BMI was misclassifying risk in both directions.

The 5 Best Alternatives to BMI

1. Waist-to-Height Ratio (WHtR) — Most Practical

WHtR divides your waist circumference by your height (in the same units). The universal guideline established by research across 14 countries: keep your waist to less than half your height — a WHtR below 0.5.

Risk categories:

• Below 0.4 — possibly underweight
• 0.4 to 0.49 — healthy (low risk)
• 0.5 to 0.59 — increased risk
• 0.6 and above — high risk

Why it beats BMI: WHtR captures fat distribution (not just total weight), adjusts for height, and uses a single cutoff that applies to both sexes and most ethnic groups. A 2012 meta-analysis covering over 300,000 adults found WHtR outperformed BMI by 4–5 percentage points in discriminating adults with adverse cardiometabolic outcomes.

Limitations: Like BMI, it doesn’t distinguish muscle from fat — a heavily muscled person with a large waist due to muscle bulk would score poorly. It also requires an accurate waist measurement, which requires knowing the correct measurement point (midpoint between lowest rib and iliac crest, not the navel).

What you need: Soft tape measure. Free. Takes under 60 seconds.

2. Waist Circumference

A simple waist measurement without height adjustment. The established risk thresholds are: women above 80 cm (31.5 in) = increased risk; above 88 cm (34.6 in) = high risk. Men above 94 cm (37 in) = increased risk; above 102 cm (40 in) = high risk.

Why it beats BMI: Captures abdominal fat, which BMI completely ignores. Multiple large studies have found waist circumference a better predictor of cardiovascular disease and metabolic syndrome than BMI.

Limitations: Doesn’t account for height — the same waist measurement carries different risk in a shorter versus taller person. Requires sex-specific thresholds. Less reliable at very high BMI where accurate measurement is harder.

What you need: Soft tape measure. Free. Takes under 60 seconds.

3. Waist-to-Hip Ratio (WHR)

Divides waist circumference by hip circumference (at the widest point of the buttocks). WHO thresholds: women above 0.85 = abdominal obesity risk; men above 0.90 = abdominal obesity risk.

Why it beats BMI: Captures fat distribution between two body regions. A low WHR (wide hips relative to waist) is associated with lower cardiovascular risk; a high WHR (wide waist relative to hips) is a strong predictor of metabolic disease. The hip measurement also accounts for whether larger body mass is being stored in a lower-risk location.

Limitations: Requires two accurate measurements instead of one. Hip measurement point (widest part of buttocks, not hip bone) is frequently measured incorrectly. WHR cannot distinguish between having small hips and having large hips from a small waist — two people with the same WHR can have very different body compositions.

What you need: Soft tape measure. Free. Takes 2–3 minutes.

4. Body Fat Percentage

Directly measures how much of your body mass is fat versus everything else (muscle, bone, organs, water). Healthy ranges are approximately 21–32% for women and 8–19% for men, though these vary by source.

Why it beats BMI: Directly measures what BMI is trying to proxy — fat mass. Distinguishes the muscular athlete from the metabolically unhealthy person at the same weight. Can detect “hidden obesity” (normal weight but high body fat) that BMI misses entirely.

Limitations: Measurement accuracy varies widely by method. Consumer bioelectrical impedance scales (stepping on a scale that sends a current through your body) can be off by 3–8 percentage points depending on hydration, recent food intake, and time of day. Skinfold calipers require a trained technician and consistent protocol. DEXA scanning is highly accurate but expensive and requires clinic access. Hydrostatic weighing is the gold standard but impractical for routine use.

What you need: Varies by method — from a £20 bioimpedance scale to a £100+ DEXA scan appointment.

5. Body Roundness Index (BRI)

A newer metric that uses waist circumference and height to estimate how “round” a person’s cross-section is. BRI scores range from roughly 1 to 15, with higher scores indicating greater roundness and higher central obesity. The formula is more complex than WHtR but produces a similar signal.

Why it’s gaining traction: A large prospective study found that individuals with BRI scores of 6.9 or higher had approximately 50% greater mortality risk than those with scores in the 4.5–5.5 range. BRI may capture abdominal obesity in a slightly more nuanced way than the linear WHtR.

Limitations: BRI is newer and has less accumulated research backing than WHtR. It is not widely used in clinical guidelines yet. The calculation requires a calculator or app — there is no simple mental rule equivalent to “keep waist under half your height.”

What you need: Tape measure and a calculator/app. Free.

Which Alternative Should You Use?

For most people, WHtR is the practical recommendation. It requires one tape measure, one measurement, corrects for height, applies to both sexes and most ethnicities with a single cutoff, and has decades of validation in large-scale studies. The rule is simple enough to apply without a calculator: your waist should be less than half your height. If it is, you’re in the healthy zone. If it isn’t, you have actionable information.

For a more complete picture, combining WHtR with body fat percentage covers both fat distribution (what WHtR captures) and total fat mass (what body fat percentage captures), addressing the main limitations of each individual metric.