Free Health & Body Calculators
Quick, private health and body calculations — your inputs stay on your device and are never shared.
🏥 Health & Body Tools 2 tools
BMI Reference Ranges
Body Mass Index is calculated as weight (kg) ÷ height² (m²). The World Health Organization defines the following ranges for adults:
| BMI Range | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Healthy weight |
| 25.0 – 29.9 | Overweight |
| 30.0 and above | Obese |
Health Disclaimer: MonkeyTactics health calculators are informational tools only and are not a substitute for professional medical advice, diagnosis, or treatment. BMI is a general screening tool and does not account for muscle mass, bone density, age, or sex differences. Always consult a qualified healthcare professional for personalised health guidance.
About these health calculators
MonkeyTactics health tools are designed to give you quick reference figures for common body measurements. The BMI Calculator supports both metric (kg/cm) and imperial (lbs/inches) inputs, while the Age Calculator handles any date combination — useful not just for birthdays but for calculating gestational age, medication schedules, or time-sensitive eligibility checks.
As with all MonkeyTactics tools, every calculation runs locally in your browser. No health data you enter is transmitted, stored, or shared.
Frequently Asked Questions
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Is BMI an accurate measure of health?
BMI is a useful screening tool but has known limitations — it does not distinguish between fat and muscle mass, and the same BMI can mean very different things for different body types, ages, and ethnicities. Use it as a general guide, not a definitive health assessment.
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Does the BMI calculator work for children?
The standard BMI formula is designed for adults aged 18 and over. BMI for children and teenagers uses age- and sex-specific percentile charts. Consult your paediatrician for an accurate assessment for anyone under 18.
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Can the age calculator work for future dates?
Yes — the age calculator accepts any two dates, past or future, making it useful for countdowns, eligibility calculations, and planning.
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Is my health data kept private?
Yes. All calculations run entirely in your browser. No weight, height, date of birth, or any other value you enter is ever sent to a server or stored anywhere. See our Privacy Policy for details.