Reverse BMI Calculator — Find Your Target Weight or Height from BMI Free

Reverse BMI Calculator — Find Your Target Weight or Height Instantly

Most BMI calculators work one way: enter your height and weight and get your BMI. But what if you already know the BMI you want and need to find the weight to reach it? That is exactly what our Reverse BMI Calculator does.

Our free tool works three ways. The standard BMI Calculator takes your height and weight and gives you your BMI with a full breakdown. The Reverse BMI Calculator takes your height and target BMI and tells you exactly what weight you need to reach. The Find Height Calculator takes your weight and target BMI and tells you what height would produce that BMI — useful for understanding how height affects BMI targets.

All three modes support metric and imperial units — centimeters and kilograms as well as feet, inches, and pounds.

What Is a Reverse BMI Calculator?

A reverse BMI calculator flips the standard BMI formula. Instead of calculating BMI from weight and height, it calculates the weight needed to achieve a specific BMI at a given height.

The standard BMI formula is BMI equals weight in kilograms divided by height in meters squared. The reverse BMI formula rearranges this to find weight: Weight equals BMI multiplied by height in meters squared.

For example, if you are 170 cm tall and want to achieve a BMI of 22, the calculation is: 22 multiplied by (1.70 multiplied by 1.70), which equals 63.5 kg. So at 170 cm height, a weight of 63.5 kg gives a BMI of exactly 22.

This is useful for setting specific, data-driven weight goals rather than vague targets like "lose weight" or "get fit."

How to Use the Reverse BMI Calculator

Using the tool above takes under 30 seconds.

For the Reverse BMI tab: select your height unit (cm or feet plus inches), enter your height, choose whether you want the result in kilograms or pounds, enter your target BMI, and click Calculate Target Weight. The result shows your exact target weight, your weight ranges for every BMI category at your height, and the BMI category your target falls into.

For the Find Height tab: enter your weight, enter your target BMI, choose your preferred height unit, and click Calculate Required Height. The result shows you what height would be needed for your given weight to equal your target BMI.

For the standard BMI Calculator tab: enter your height and weight and click Calculate My BMI. The result shows your BMI with an animated scale indicator, your position relative to all four BMI categories, and the weight ranges for each category at your height.

Reverse BMI Calculator — Complete Examples

These examples show how the reverse BMI calculation works across different heights and target BMIs.

At 155 cm height, a BMI of 18.5 requires a weight of 44.4 kg, a BMI of 22 requires 52.8 kg, and a BMI of 24.9 requires 59.8 kg. The healthy weight range at 155 cm is 44.4 to 59.8 kg.

At 165 cm height, a BMI of 18.5 requires a weight of 50.3 kg, a BMI of 22 requires 59.9 kg, and a BMI of 24.9 requires 67.7 kg. The healthy weight range at 165 cm is 50.3 to 67.7 kg.

At 170 cm height, a BMI of 18.5 requires a weight of 53.5 kg, a BMI of 22 requires 63.5 kg, and a BMI of 24.9 requires 72.0 kg. The healthy weight range at 170 cm is 53.5 to 72.0 kg.

At 175 cm height, a BMI of 18.5 requires a weight of 56.7 kg, a BMI of 22 requires 67.4 kg, and a BMI of 24.9 requires 76.3 kg. The healthy weight range at 175 cm is 56.7 to 76.3 kg.

At 180 cm height, a BMI of 18.5 requires a weight of 59.9 kg, a BMI of 22 requires 71.3 kg, and a BMI of 24.9 requires 80.7 kg. The healthy weight range at 180 cm is 59.9 to 80.7 kg.

At 185 cm height, a BMI of 18.5 requires a weight of 63.3 kg, a BMI of 22 requires 75.3 kg, and a BMI of 24.9 requires 85.2 kg. The healthy weight range at 185 cm is 63.3 to 85.2 kg.

Calculate Height from BMI and Weight

The Find Height tab on our calculator solves a different version of the reverse BMI problem: given a known weight and a target BMI, what height would produce that BMI?

The formula for this is: Height in meters equals the square root of (weight in kilograms divided by BMI).

For example, if you weigh 80 kg and want a BMI of 22: the square root of (80 divided by 22) equals 1.905 meters, or 190.5 cm. This means at a weight of 80 kg, a person needs to be approximately 190.5 cm tall to have a BMI of 22.

This calculation is used to understand how much height influences BMI targets, to see what BMI a given weight would produce at different heights, and to plan realistic targets when height is a known fixed factor.

What Is BMI and Why Does It Matter?

BMI stands for Body Mass Index. It is a screening tool used by healthcare providers worldwide to assess whether a person's weight falls within a healthy range for their height. The World Health Organization and health authorities in most countries use BMI as a primary population health indicator.

The four BMI categories are underweight for BMI below 18.5, normal weight for BMI between 18.5 and 24.9, overweight for BMI between 25.0 and 29.9, and obese for BMI of 30.0 and above.

BMI is useful as a general screening tool but has well-documented limitations. It does not directly measure body fat percentage, so highly muscular individuals often have high BMI scores despite having very low body fat. It also does not account for where fat is distributed on the body — abdominal fat carries higher health risks than fat stored in other areas. Age and ethnicity can affect the health implications of a given BMI score.

Despite these limitations, BMI remains the most widely used initial screening tool for weight-related health assessment because it requires only height and weight measurements, is quick to calculate, and provides a useful population-level indicator of weight-related health risk.

Reverse BMI Calculator for Men and Women

The BMI formula is identical for men and women — weight in kilograms divided by height in meters squared — so the mathematical result of our reverse BMI calculator is the same regardless of gender. However gender is included as an input because some health contexts use gender-adjusted BMI interpretations.

For men, BMI targets that reflect healthy body composition often sit toward the middle of the normal range around 21 to 23, because men generally carry more muscle mass than the BMI formula accounts for. A muscular man with low body fat may show a BMI of 26 or 27 while being metabolically healthy.

For women, BMI interpretation is similarly nuanced. Women generally have a higher percentage of body fat than men at equivalent BMI values, which is normal and healthy. The same BMI range of 18.5 to 24.9 applies, but individual body composition goals may differ.

For both men and women, the reverse BMI calculator is most useful as a planning tool for setting a specific measurable weight target based on a BMI goal, rather than as a definitive statement about ideal health.

How to Calculate Reverse BMI Manually

If you want to check the calculator results manually, here is the step-by-step process.

First, convert your height to meters. If your height is in centimeters, divide by 100. If your height is in feet and inches, multiply the feet by 0.3048 and the inches by 0.0254 and add them together.

Second, square your height in meters. Multiply the height value by itself.

Third, multiply the squared height by your target BMI. This gives your target weight in kilograms.

Fourth, if you need the result in pounds, multiply the kilograms result by 2.20462.

Example: Height 5 feet 8 inches, target BMI 22. Converting: (5 multiplied by 0.3048) plus (8 multiplied by 0.0254) equals 1.524 plus 0.2032, equals 1.7272 meters. Squaring: 1.7272 multiplied by 1.7272 equals 2.983. Multiplying by BMI: 22 multiplied by 2.983 equals 65.6 kg. Converting to pounds: 65.6 multiplied by 2.20462 equals 144.6 lbs.

Practical Uses for the Reverse BMI Calculator

Setting weight loss goals is the most common use. Instead of picking an arbitrary weight target, the reverse BMI calculator lets you set a specific BMI target in the healthy range and calculate exactly what weight that corresponds to for your height.

Planning fitness milestones works similarly. You can calculate the weight corresponding to BMI 24 as a first milestone, then BMI 22 as a second milestone, giving you specific numbers to track progress against.

Medical and nutritional planning sometimes uses BMI targets. Healthcare providers may set a target BMI for patients in weight management programs, and the reverse BMI calculator converts this into a concrete weight target.

Understanding the relationship between height and weight is another use. Many people find it helpful to see the complete weight range for their height across all four BMI categories — the range cards in our tool show exactly this.

Limitations of BMI — What the Calculator Cannot Tell You

BMI is a population-level screening tool and has important limitations when applied to individuals.

Athletes and highly muscular individuals frequently have BMI scores in the overweight or even obese range despite having low body fat percentages and excellent metabolic health. The BMI formula has no way to distinguish between muscle mass and fat mass.

Older adults may have normal BMI scores while having reduced muscle mass and increased body fat — a condition called sarcopenic obesity — which carries significant health risks not captured by BMI.

Ethnicity affects the health implications of BMI. Research has found that people of Asian descent have higher health risks at lower BMI values than people of European descent, which is why some health authorities in Asian countries use different BMI thresholds.

Children and teenagers should not use adult BMI calculations. Child BMI uses age and sex-specific percentile charts rather than the fixed category thresholds used for adults.

For a more complete picture of health and body composition than BMI alone provides, work with a healthcare provider who can assess additional markers including waist circumference, body fat percentage, blood pressure, blood glucose, and cholesterol levels.

Frequently Asked Questions About the Reverse BMI Calculator

What is a reverse BMI calculator?

A reverse BMI calculator takes your height and a desired target BMI and calculates the weight you need to reach that BMI. It is the opposite of a standard BMI calculator which takes weight and height and gives you the BMI.

How do I calculate weight from BMI and height?

The formula is: Weight equals BMI multiplied by height in meters squared. For example at 170 cm height (1.70 m) with a target BMI of 22: 22 multiplied by (1.70 multiplied by 1.70) equals 63.5 kg. Use our calculator above for instant results in kg or lbs.

How do I calculate height from BMI and weight?

The formula is: Height in meters equals the square root of (weight in kilograms divided by BMI). Use the Find Height tab in our calculator to get instant results in cm or feet.

Is reverse BMI calculator the same for men and women?

The mathematical formula is identical for men and women. BMI does not have a gender-specific calculation. However gender differences in body composition mean that the same BMI may represent different body fat percentages in men versus women, which is why some health assessments use gender-specific interpretations alongside BMI.

What is a healthy BMI to aim for?

The WHO defines the healthy BMI range as 18.5 to 24.9 for adults. Many health practitioners suggest aiming for the middle of this range around 21 to 23 as an optimal target, though individual health circumstances vary. Always discuss specific weight goals with a healthcare provider.

Can I use the reverse BMI calculator in pounds and feet?

Yes. Our calculator supports both metric (cm and kg) and imperial (feet, inches, and pounds) units. Select your preferred units before entering your values.

What weight do I need to be for a BMI of 25?

This depends on your height. Use the Reverse BMI tab in our calculator above — enter your height and enter 25 as the target BMI to get your exact answer. As a reference, at 170 cm height a BMI of 25 corresponds to 72.3 kg or approximately 159 lbs.

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