Calculate ideal waist size from height and sex, check waist-to-height ratio, and estimate BMI-based waist targets in inches or cm for screening.
Disclaimer: This is not medical advice. There is no perfect ideal waist size. This is simply a guide for understanding the average waist size at an average BMI.
- All Health and Medical Calculators
- Waist to Height Ratio Calculator / WHtR Calculator
- Waist to Hip Ratio Calculator
- Ideal Weight Calculator
Ideal Waist Size Formula
The calculator uses three formulas depending on the tab you choose.
Ideal waist estimate based on height and sex:
Ideal Waist (in) = 0.45 × Height (in) + offset
Waist-to-height ratio (WHtR):
WHtR = Waist / Height
Body Mass Index (BMI):
BMI = Weight (kg) / Height (m)^2
- Height: your standing height in inches, feet, centimeters, or meters.
- Waist: circumference measured at the navel, relaxed and unflexed.
- Offset: -3 inches for males, -2 inches for females.
- Weight: body weight in pounds, kilograms, or stone.
- WHtR target: keep waist below half your height (ratio under 0.50).
The Ideal waist tab returns a target circumference from height and sex, and compares it to your current waist if you enter one. The Waist check tab returns your WHtR and the maximum waist that keeps you under 0.50. The BMI + waist tab returns BMI plus the ideal waist estimate, and adds WHtR if you enter a waist value.
Reference Tables
Use these tables to interpret the numbers the calculator returns.
| WHtR | Category |
|---|---|
| Below 0.40 | Below typical adult range |
| 0.40 to 0.49 | Healthy target |
| 0.50 to 0.59 | Increased risk |
| 0.60 and above | High risk |
| Height | Ideal waist (male) | Ideal waist (female) | Max at WHtR 0.50 |
|---|---|---|---|
| 5'2" (62 in) | 24.9 in | 25.9 in | 31.0 in |
| 5'6" (66 in) | 26.7 in | 27.7 in | 33.0 in |
| 5'10" (70 in) | 28.5 in | 29.5 in | 35.0 in |
| 6'0" (72 in) | 29.4 in | 30.4 in | 36.0 in |
| 6'2" (74 in) | 30.3 in | 31.3 in | 37.0 in |
Examples and FAQ
Example 1. A 5'10" male enters height 70 in. The formula gives 0.45 × 70 - 3 = 28.5 in for the ideal waist. The WHtR cap of 0.50 sets the upper limit at 35 in.
Example 2. A 5'4" female with a 30 in waist enters both values into the Waist check tab. WHtR = 30 / 64 = 0.469, which falls in the healthy target range.
How should I measure my waist? Stand relaxed, exhale normally, and wrap a flexible tape around the narrowest point between your lowest rib and the top of your hip bone. Most people measure at the navel.
Why does the formula use 0.45 of height? It approximates the waist of a lean adult and lines up closely with the WHtR 0.50 health cutoff. The small sex offset reflects average differences in trunk shape.
Is the ideal waist the same as a healthy waist? No. The ideal value is a lean target. The healthy cutoff is your height divided by two. Anything below that line is generally considered low risk for adults.
Does this work for athletes or very muscular people? The WHtR target still applies because it tracks abdominal size, not weight. BMI can read high for muscular builds, so use waist and WHtR as the primary check in that case.
