BMI Calculator
Find out your Body Mass Index in seconds. Enter your height and weight below — metric or imperial, your choice.
Now do something about it
Knowing your BMI is step one. Caldef helps you take action — log meals by just describing what you ate, get a personalized calorie deficit, and track your weight toward a healthy range.
Describe Your Meal
No barcode scanning. Type what you ate and AI breaks down every macro instantly.
Personal Deficit Target
Caldef calculates exactly how many calories you need to reach your goal weight.
Watch Your Progress
Log your weight daily and see your trend move toward a healthy BMI range.
Free download · 7-day free trial
About BMI
What is BMI?
Body Mass Index (BMI) is a number calculated from your weight and height. It's a widely used screening tool to categorize whether a person is underweight, normal weight, overweight, or obese. The formula is: BMI = weight (kg) ÷ height² (m²).
What is a healthy BMI?
For most adults, a BMI between 18.5 and 24.9 is considered a healthy weight. Below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is classified as obese. These ranges apply to adults aged 20 and older.
Is BMI accurate?
BMI is a useful starting point but doesn't directly measure body fat. It can overestimate fat in muscular individuals and underestimate it in older adults who have lost muscle mass. Use it alongside other metrics and consult a healthcare professional for a complete picture.
What should I do after calculating my BMI?
If your BMI is above the healthy range, the most effective approach is tracking your calorie intake and creating a moderate calorie deficit. Caldef calculates your personal deficit target and lets you log meals by taking a photo of your meal or describe what you ate.
Ready to transform your health?
Join thousands of users who have discovered the simplest way to track calories and reach their weight loss goals — powered by AI.
Free download · 7-day free trial