Reverse BMI Calculator
Enter your height and your target BMI to estimate the body weight that matches that BMI.
What Is a Reverse BMI Calculator?
A traditional BMI calculator tells you your BMI after you enter your current height and weight. A reverse BMI calculator flips that process: you enter your height and your target BMI, and the tool estimates the body weight that would correspond to that BMI.
This can be useful when you are planning a structured weight-loss or weight-gain phase and want a practical number to work toward. Instead of asking, “What is my BMI now?”, you ask, “What weight puts me near BMI 21, 22, or 25?”
How the Formula Works
Metric formula
Weight (kg) = BMI × Height (m)2
Imperial formula
Weight (lb) = BMI × Height (in)2 ÷ 703
Because height is squared, even small changes in height can noticeably affect target weight. That is why accurate height input is important.
How to Use This Calculator
- Select Metric or Imperial units.
- Enter your height.
- Enter your target BMI (common targets are 20–25 for many adults).
- Optionally add your current weight to see how much to gain or lose.
- Click Calculate Target Weight.
BMI Categories (General Adult Reference)
- Underweight: below 18.5
- Normal range: 18.5 to 24.9
- Overweight: 25.0 to 29.9
- Obesity: 30.0 and above
The calculator also shows the weight range corresponding to BMI 18.5–24.9 for your entered height, so you can compare your target with the typical reference range.
Example Reverse BMI Calculations
Example 1 (Metric)
Height: 170 cm (1.70 m), target BMI: 22
Target weight = 22 × 1.70² = 63.6 kg (about 140.2 lb)
Example 2 (Imperial)
Height: 5'10" (70 in), target BMI: 25
Target weight = 25 × 70² ÷ 703 = 174.3 lb (about 79.1 kg)
Why Use a Reverse BMI Tool?
- Turns an abstract BMI goal into a concrete target weight.
- Helps set realistic short-term milestones.
- Makes it easier to discuss plans with a coach, trainer, or clinician.
- Lets you compare multiple BMI targets quickly.
Important Limitations of BMI
BMI is a screening metric, not a complete health diagnosis. It does not directly measure body fat, muscle mass, bone density, fat distribution, or fitness level. A muscular person may have a high BMI but low body fat, while another person may have a “normal” BMI and still carry excess visceral fat.
Use BMI as one data point alongside waist measurements, training performance, blood markers, sleep quality, and how you feel physically and mentally.
Set Better Goals Than “Weight Alone”
Useful companion metrics
- Waist circumference
- Weekly average body weight trend
- Strength and endurance performance
- Daily energy levels and sleep quality
- Nutrition consistency and protein intake
Pacing your progress
Sustainable changes are usually gradual. Many people do best targeting a slow, steady rate of change rather than aggressive cuts or rapid bulking. Consistency usually beats intensity over the long run.
FAQ
Is this calculator for adults only?
Yes. Standard adult BMI formulas are not interpreted the same way for children and teens. Pediatric growth charts should be used for younger age groups.
What target BMI should I choose?
It depends on your context, health history, and goals. Many adults choose a target somewhere in the 20–25 range, but personal recommendations should come from a qualified healthcare professional.
Can I trust BMI if I lift weights?
BMI may overestimate fatness in highly muscular individuals. In that case, combine BMI with waist measures, body-composition estimates, and performance data for better decisions.
Educational use only. This tool does not replace medical advice, diagnosis, or treatment.