Reverse BMI Calculator

Enter your height and target BMI to calculate the corresponding weight in pounds or kilograms. You can also view the adult BMI category and healthy-weight range for your height.

A reverse BMI calculator works backward from the standard BMI formula. Instead of using height and weight to calculate BMI, it uses height and a selected BMI to calculate the corresponding adult reference weight.

Height & Unit Setup

Choose the measurement system and enter adult height.

Underweight

Below 18.5

Adult BMI category used for screening and population-level comparison.

Healthy weight

18.5 to <25

Adult BMI category used for screening and population-level comparison.

Overweight

25 to <30

Adult BMI category used for screening and population-level comparison.

Class 1 obesity

30 to <35

Adult BMI category used for screening and population-level comparison.

Class 2 obesity

35 to <40

Adult BMI category used for screening and population-level comparison.

Class 3 obesity

40 or greater

Adult BMI category used for screening and population-level comparison.

Weight for Common BMI Values

These reference weights update from the height entered above and show common adult BMI thresholds.

BMIMeaningWeight (lb)Weight (kg)
18.5Lower healthy-weight boundary125.356.8
20Example within healthy category135.461.4
22Example within healthy category14967.6
24.9Just below overweight threshold168.676.5
25Overweight threshold169.376.8
30Obesity threshold203.292.1

How to Use the Reverse BMI Calculator

Choose US or metric units, enter your height, then select a target BMI or type your own value. The calculator solves the standard BMI equation backward to estimate the weight that corresponds to that BMI.

1

Enter adult height in feet and inches, or centimeters.

2

Pick a target BMI preset or use the slider for a custom target.

3

Optionally add current weight to see the difference from the target.

4

Use the healthy range output to compare the full CDC healthy BMI band.

Adult BMI Notes

The CDC describes BMI as weight in kilograms divided by height in meters squared and classifies adults 20 and older using CDC adult BMI categories.

  • Healthy adult BMI category: 18.5 to less than 25.
  • Overweight category starts at BMI 25.
  • Obesity category starts at BMI 30 and is divided into classes.
  • BMI is not a substitute for professional medical advice.

Reverse BMI Formula

The standard BMI formula divides weight by height squared. Reverse BMI multiplies the target BMI by height squared to solve for target weight.

Metric

Target kg = BMI x height(m)^2

US customary

Approx. target lb = BMI x height(in)^2 / 703

Example height

69 total inches

5 ft 9 in

Target BMI

Example within the adult healthy-weight category

22

Target weight

Traditional US approximation: 22 x 69 x 69 / 703

149 lb

Healthy range

BMI 18.5 to less than 25 at 5 ft 9 in

125.3 lb to less than 169.3 lb

What the Result Means

The output is a mathematical weight estimate for a selected BMI. It can help with planning conversations, but it cannot determine body composition, nutritional status, or whether weight change is appropriate.

Safety Guidelines

This calculator is for education only. Seek professional guidance before pursuing intentional weight loss or gain if you are pregnant, postpartum, under 20, managing chronic disease, recovering from illness, or have a history of disordered eating.

Use adult BMI categories only for adults 20 and older.
Do not use BMI alone to judge health or fitness.
Consider waist measurement, labs, symptoms, and history.
Avoid rapid weight change without clinical supervision.

Reverse BMI FAQ

Common questions about target BMI weight calculations.

What is a reverse BMI calculator?

A reverse BMI calculator starts with height and a target BMI, then solves the BMI formula backward to estimate the weight that would produce that BMI.

What is the reverse BMI formula?

The metric formula is Target weight in kg = target BMI x height in meters squared. The traditional US formula uses 703 as a rounded conversion factor; this calculator calculates in SI units and then converts to pounds.

Is BMI a diagnosis?

No. BMI is a screening measure, not a diagnosis. It does not directly measure body fat, muscle mass, lab values, medical history, or fitness.

What BMI target should I use?

For adults 20 and older, the CDC healthy weight category is 18.5 to less than 25. A personal target should be discussed with a clinician if weight change is medically important.

Can this be used for children or teens?

No. Children and teens use age- and sex-specific BMI percentiles, not fixed adult BMI thresholds.

How do I calculate weight from BMI?

Multiply the target BMI by height in meters squared to get kilograms. To convert kilograms to pounds, divide by 0.45359237.

What weight is a BMI of 25 for my height?

It depends on height. Enter 25 as the target BMI and the calculator will show the weight that corresponds to the adult overweight threshold.

Is reverse BMI the same as ideal weight?

No. Reverse BMI calculates the weight for a selected BMI and height. Ideal-weight calculators may use separate formulas that include sex, height, or frame assumptions.

Does target BMI differ for men and women?

The standard adult BMI formula and CDC adult BMI categories do not change by sex, though BMI has individual limitations and does not measure body composition.

Can athletes use this calculator?

Athletes can calculate the mathematical result, but BMI may misrepresent body composition in people with high muscularity.

Does this work during pregnancy?

No. This calculator should not be used to set pregnancy weight targets. Pregnancy-specific clinical guidance is needed.

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