Reverse BMI Calculator: Find Your Target Weight (2026)
Trying to work out what your weight would be at a specific BMI can be confusing, especially when you need the answer in kg, pounds, or stones. Use our reverse BMI calculator to find out your target weight, explore the healthy weight range for your height, and see how much your weight needs to change to reach your goal.
Reverse BMI Calculator
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What Your Result Means
Your reverse BMI calculation shows the exact target weight that matched your chosen target BMI based on your height.
The healthy weight range provided is calculated using the standard adult BMI boundaries of 18.5 to 24.9. If you entered your current weight, the tool estimates how much weight you need to lose or gain to hit your goal.
Reverse BMI Formula
Wondering how we calculate weight from BMI? The mathematics depend on whether you use the metric or imperial system.
BMI Categories Table (For Males and Females)
The World Health Organization (WHO) and NHS classify adult body mass index into the following main categories. The standard BMI calculation does not distinguish between male and female bodies. The same healthy range applies to both genders, though body composition (like muscle mass in men or healthy fat distribution in women) can naturally vary.
| Category | BMI Range | General Guidance |
|---|---|---|
| Underweight | Below 18.5 | Consider speaking with a GP about safe weight gain. |
| Healthy weight | 18.5 to 24.9 | Associated with optimal long-term health and well-being. |
| Overweight | 25 to 29.9 | A gradual, healthy weight loss plan is often advised. |
| Obesity | 30 and above | Medical weight management guidance is highly recommended. |
Average Target Weight
To give you a quick visual idea, here is what a target BMI of 22.5 (Middle Healthy) looks like for an average male and female in the UK:
Average Male
(10 st 12 lbs)
Average Female
(9 st 1 lbs)
Important BMI Limitations
While a BMI weight calculator is a useful screening guide, it has limitations. BMI does not directly measure body fat percentage, muscle mass, or fat distribution (such as waist measurement). Athletes, pregnant people, children, and teenagers may need different guidance. Always view BMI as an estimate rather than a complete picture of your overall health.
FAQs
What is a reverse BMI calculator?
A reverse BMI calculator works backwards from the standard BMI formula. Instead of using your weight and height to find your BMI, it uses your target BMI and height to calculate the exact weight you need to be to reach that goal.
How do I calculate weight from BMI?
You multiply your target BMI by the square of your height in metres. If you want the result in pounds, you multiply the target BMI by your height in inches squared, then divide by 703. Our reverse BMI calculator does all this maths for you automatically.
What BMI should I aim for?
For most adults, the NHS and NICE guidance suggest aiming for a healthy BMI range between 18.5 and 24.9. A target BMI of 22.5 is often used as a solid middle-ground goal.
Can I use this calculator in stones and pounds?
Yes. Simply select the "Imperial/UK" option on the calculator. You can enter your height in feet and inches, and it will output your target weight in stones and pounds, as well as kilograms and pure pounds.
Is BMI accurate for everyone?
No. BMI limitations mean it may not be accurate for people with high muscle mass (like bodybuilders), some ethnic groups, pregnant women, or the elderly. It estimates body mass but cannot distinguish between fat and muscle.
Can children or teenagers use this calculator?
No, this adult BMI calculator is meant for people aged 18 and over. Children and teenagers are still growing, so their healthy weight ranges rely on age and gender-specific centile charts, not standard adult BMI boundaries.
Why does my result show a healthy weight range?
Your healthy weight range shows the minimum and maximum weights that keep you within the 18.5 to 24.9 BMI category. Knowing this range helps you set a realistic weight management or fitness goal without focusing on just one specific number.