Body Mass Index (BMI) is a common metric used to assess overall health. It’s a number calculated using your weight and height to categorize you into different weight statuses.
A “reverse BMI calculator” does just what it sounds like: it lets you determine what weight you’d need to be to achieve a specific BMI.
This article provides a complete guide to understanding and using reverse BMI calculations to help you reach your health goals.
Understanding Body Mass Index (BMI)
Body mass index (BMI) is a quick way to estimate your body fat based on your weight and height. Keep in mind that it’s just an estimate and not a precise measurement.
You can calculate your BMI by dividing your weight in kilograms (kg) by your height in meters (m) squared:
BMI = weight (kg) / height (m)2
If you’re in the U.S. and prefer to use pounds and inches, the formula is:
BMI = 703 x weight (lb) / height (in)2
Once you have your BMI number, you can use these categories to see where you fall:
- Underweight: BMI less than 18.5
- Normal weight: BMI of 18.5 to 24.9
- Overweight: BMI of 25 to 29.9
- Obese: BMI of 30 or higher
It’s important to remember that BMI has limitations. It doesn’t consider things like muscle mass, bone density, age, sex, or where your body stores fat. So, it’s just one piece of the puzzle when assessing your overall health.
Reverse BMI: What is it?
A reverse BMI calculator helps you figure out how much you’d have to weigh to reach a certain BMI. Instead of plugging in your height and weight to find your BMI, you plug in your height and desired BMI to find out what weight corresponds to that number.
Why would you want to use a reverse BMI calculator?
- Goal setting. If you have a certain BMI in mind, you can use a reverse BMI calculator to figure out how many pounds you’d need to lose or gain to reach that goal.
- Weight management. Once you know how many pounds you need to lose or gain, you can work with a healthcare professional to develop a safe, effective plan.
- Understanding BMI. Playing around with a reverse BMI calculator can give you a better, more tangible sense of the relationship between BMI, height, and weight.
How to Calculate Weight from BMI
Want to know what weight would put you at a BMI of, say, 22? Here’s how to calculate it.
The Reverse BMI Formula
Here’s the formula for calculating weight (W) from BMI and height (H) in inches: W = (BMI H2) / 703.
If you’re working in the metric system, here’s the formula: W = BMI H2 (where H is in meters and W is in kilograms).
Step-by-Step Calculation
- Decide what you want your BMI to be (somewhere between 18.5 and 24.9 is considered a healthy range).
- Measure your height in inches or meters.
- Plug those numbers into the correct formula to calculate the weight that would give you the BMI you’re seeking.
Example Calculation
Here’s an example: Say you’re 5’5″ (65 inches), and you want a BMI of 22. The calculation would look like this: W = (22 652) / 703 = 132.5 lbs (approximately).
Factors to consider when using a reverse BMI calculator
While it can be fun to play around with numbers to find your ideal weight, it’s important to keep in mind that BMI isn’t the only measurement to consider when assessing your overall health and wellness.
Body composition
BMI doesn’t take into account your ratio of muscle mass to fat. If you’re an athlete or someone with a lot of muscle, your BMI may be higher than average even though you may be at a healthy weight.
Individual body types
Ideal BMI can also vary somewhat depending on your body type, age, and sex. Your healthcare provider can help you determine what a healthy BMI range is for you.
Health goals
BMI is just one piece of the puzzle. Blood pressure, cholesterol levels, and activity level are also important factors to consider when you’re trying to reach your health and wellness goals.
What are the limitations of BMI and reverse BMI calculations?
It’s important to remember that BMI is a screening tool, not a diagnostic tool. It can suggest that someone might be underweight, overweight, or have obesity, but it can’t diagnose those conditions.
A reverse BMI calculation is only as accurate as the original BMI calculation, which means it shares the same limitations.
So, while these tools can be helpful for preliminary assessments, it’s always best to seek a comprehensive health evaluation from your doctor.
Wrapping Up
A reverse BMI calculator is a useful tool for estimating the weight needed to reach a specific BMI. It can help you set goals for yourself, but it can’t tell you how healthy you are.
Remember that BMI is just one measure of health. Talk with your doctor about your individual circumstances and what weight is right for you.
Used along with other health metrics and professional advice, a reverse BMI calculator can be a helpful part of your overall wellness plan.