Body composition
Waist-to-Hip Ratio Calculator
Calculate waist-to-hip ratio and assess body composition using WHO guidelines.
Result
Risk threshold position
Against the WHO cut-off for men (0.90).
How to use it
- Measure your waist midway between the lowest rib and the top of the hip bone, at the end of a normal breath out (the WHO protocol), and your hips around the widest part of the buttocks. Stand relaxed with the tape level. Enter both in cm, or inches with Units set to US.
- The WHO cut-off for a substantially increased risk of metabolic complications is a ratio of 0.90 or more in men and 0.85 or more in women. The calculator also flags the 0.05 just below the cut-off as close to it.
- WHR is a stronger cardiovascular risk predictor than BMI because it specifically captures central/abdominal fat distribution — the metabolically active, inflammation-promoting fat depot surrounding organs.
- Track WHR monthly during a cut alongside scale weight: the two do not always move together, and the tape shows changes in fat distribution that the scale cannot.
- If your WHR falls in high-risk territory, the primary intervention is a sustained calorie deficit (300–500 below TDEE). Spot reduction does not exist — abdominal fat decreases as part of overall fat loss.
Questions people usually ask
Where should I measure waist circumference?
WHO protocol: measure horizontally midway between your lowest rib and the top of your hip bone, at the end of a normal breath out. Stand relaxed with the tape snug but not tight.
Where should I measure hip circumference?
Measure at the widest point around your buttocks, keeping the tape horizontal and snug but not tight.
What does waist-to-hip ratio indicate?
WHR is a body composition metric that can correlate with health risk. Lower ratios generally suggest a healthier fat distribution pattern.
Why are the risk ranges different for males and females?
Biological differences in typical fat distribution patterns mean different WHR thresholds for males and females according to WHO guidelines.
Is this the only body composition metric I should use?
No. WHR is most useful alongside other metrics like BMI, body fat percentage, and waist circumference alone.
Is this tool free and private to use?
Yes. AI Fit Hub tools are free, no-signup browser tools. Inputs stay in your browser unless you choose to share a URL.
Do these tools replace medical guidance?
No. These outputs are general fitness estimates — not medical advice.
Can I switch between metric and imperial units?
Yes. Every tool supports both systems and remembers your preference in localStorage.
The formula, worked through
- Formula Waist-to-Hip Ratio Formula
Computes waist-to-hip ratio as waist circumference divided by hip circumference; WHO cardiometabolic risk cutoffs are 0.90 for men and 0.85 for women.
- Formula BMI Formula
BMI = weight in kilograms divided by height in meters squared. Quick screening number, blind to body composition. Cutoffs are 18.5 / 25 / 30 (WHO).
- Formula Body Fat Percentage Formula (US Navy)
US Navy circumference-based body fat. Men: 86.010·log10(waist−neck) − 70.041·log10(height) + 36.76. Women: 163.205·log10(waist+hip−neck) − 97.684·log10(height) − 78.387.
Related calculators
- Body composition Body Fat Percentage Calculator
Estimate body fat percentage using the U.S. Navy circumference method.
- Nutrition TDEE Calculator
Estimate your daily energy expenditure with Mifflin-St Jeor + activity factors.
- Nutrition Macro Calculator
Convert calorie targets into protein, carbs, and fat grams for your goal.
- Planning Calorie Deficit Calculator
Estimate required daily calorie deficit for a target timeline and bodyweight change.
Background on the Waist-to-Hip Ratio Calculator
- Guide How to Track Body Fat Accurately
How to track body fat reliably. Standardize tape and caliper measurements, time them right, and turn the data into real body composition progress.
- Comparison How Accurate Is the Navy Body Fat Calculator vs Calipers
How accurate is the Navy body fat calculator? It reads within 3-4% of DEXA versus 2-3% for trained calipers. Navy wins on repeatability for solo tracking.
Articles
- 7 min read How to Measure Body Fat at Home
Measure body fat at home: skinfold calipers, bioelectrical impedance, Navy method, and DEXA reality-check — accuracy, error bands, and method choice.
- 4 min read How to Stretch Hip Flexors: Best Stretches and Hold Times
Stretch tight hip flexors with a half-kneeling stretch and pelvic tuck: hold about 30 seconds, 60 seconds per side, 2-3 days a week. What the trials show.
By goal
Use it from code
The same calculation as a JavaScript module you can import. It runs where you import it, with no request, key or rate limit.
import { compute } from "https://aifithub.io/engines/waist-to-hip-ratio-calculator.js";Input and output contract, TypeScript types and the guide for agents.