1.75 m and 70 kg
In metric mode with height 175 cm and weight 70 kg, BMI = 70 / 1.75² = 22.86, which falls in the WHO normal band (18.5–24.9).
| Input | Value |
|---|---|
| system | metric |
| heightCm | 175 |
| weightKg | 70 |
| Result | BMI 22.86 · normal weight |
Free BMI Calculator
Calculate your Body Mass Index from metric or imperial measurements, with the WHO classification and a healthy weight range.
The BMI calculator computes your Body Mass Index from height and weight and places it in the World Health Organization classification: underweight (below 18.5), normal weight (18.5–24.9), overweight (25–29.9), and obesity (30 and above). You can enter metric units (centimeters and kilograms) or imperial units (feet, inches, and pounds) — the imperial values are converted with the exact definitions of the inch and the pound before the BMI is computed, so both systems produce identical results. Alongside the BMI value and category, the tool shows the healthy weight range for your height (the 18.5–24.9 band), so you can see at a glance how far a weight sits outside it. The calculation is the standard formula BMI = weight(kg) / height(m)², applied to the unrounded value so boundary cases classify correctly. Everything runs locally in your browser; height and weight never leave your device.
Processed locally in your browser
Your BMI
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Category
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Healthy weight for your height
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WHO classification applied to the unrounded value. BMI is a screening index for adults, not a diagnosis.
How is the result calculated?
5 ft 9 in and 150 lb
In imperial mode, the tool converts 5 ft 9 in to 1.7526 m and 150 lb to 68.04 kg, then computes BMI ≈ 22.15 — the same method as the metric path.
| Input | Value |
|---|---|
| system | imperial |
| heightFt | 5 |
| heightIn | 9 |
| weightLb | 150 |
| Result | BMI 22.15 · normal weight |
What is the formula and its assumptions?
Body Mass Index
BMI = weight(kg) / height(m)²
| Symbol | Meaning |
|---|---|
weight | body mass in kilograms |
height | height in meters (cm / 100) |
WHO classification bands
under 18.5 underweight · 18.5–24.9 normal · 25–29.9 overweight · 30+ obese
| Symbol | Meaning |
|---|---|
18.5 | lower bound of the normal band (inclusive) |
30 | lower bound of the obese band (inclusive) |
What are the most common mistakes?
- Entering height in meters instead of centimeters in metric mode — 1.75 instead of 175 shifts the BMI by a factor of 100.
- Entering 12 or more inches in the feet-plus-inches field — 5 ft 12 in should be entered as 6 ft 0 in.
- Treating a high BMI as a diagnosis rather than a screening result — BMI alone does not measure body fat percentage.
What are the assumptions and limitations?
- The WHO bands are validated for adults; they are not appropriate for children, teenagers, pregnant women, or people with high muscle mass.
- BMI does not distinguish fat from muscle and does not capture fat distribution (e.g. waist circumference).
- This tool is informational only and does not replace a medical evaluation.
Where do the numbers come from?
Last reviewed August 11, 2026 · Version 1.0.0 · Toolivaro does not guarantee external content.
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Frequently asked questions
Is BMI a diagnosis?
No. BMI is a screening index developed for population-level studies. It correlates with body fat for most adults, but it does not measure body composition — muscular individuals can have a high BMI with low body fat, and the index says nothing about where fat is distributed. Use it as one signal among several, and discuss health questions with a professional.
Why does the healthy range show 18.5–24.9?
Those are the WHO cut-offs: 18.5 and below is underweight, 18.5–24.9 is normal weight, 25–29.9 is overweight, and 30 and above is obesity. The calculator applies them to the unrounded BMI so a value of exactly 25.0 classifies as overweight, not normal.
Do the metric and imperial modes give different results?
No. The imperial mode converts inches and pounds to meters and kilograms using their exact definitions before applying the same formula, so both modes produce the same BMI for the same physical measurements (differences of less than a hundredth are rounding only).
Found a mistake or have a correction? Report it — we review every correction.
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Reviewed by the Toolivaro editorial team per our methodology Methodology · Editorial policy