Ideal Body Weight Calculator

Estimate ideal body weight (IBW) from the sex option and height you enter using the Devine formula. Choose centimeters or feet and inches; the calculator converts height to inches and reports one reference value in kilograms to one decimal place. This is a formula-based screening and planning estimate, not an assessment of body composition, a diagnosis, or a medically prescribed target.

How to Use the Ideal Body Weight Calculator

Calculate a Devine-formula reference from height and the formula’s male or female option. The result is a screening and planning estimate only; it does not determine a healthy personal weight or diagnose any condition.

  1. Choose metric (cm) or imperial (ft/in).
  2. Select male or female, the two sex-specific options implemented by the Devine formula.
  3. Enter height in centimeters or as feet and inches; switching units converts a valid current height.
  4. Press Calculate to see estimated ideal body weight in kilograms to one decimal place.
  5. Review the explanation and the displayed inches over 5 feet.
  6. Use Reset to restore the default inputs before trying another synthetic scenario.

Formula and methodology

The calculator converts height to total inches and sets inches over 5 feet to max(0, total inches − 60). Male IBW = 50.0 kg + 2.3 kg × inches over 5 feet. Female IBW = 45.5 kg + 2.3 kg × inches over 5 feet. The result is rounded to one decimal place.

Metric input is accepted from 120 to 250 cm and imperial input from about 4 ft 0 in to 8 ft 0 in. For accepted heights at or below 5 feet, the implementation uses zero additional inches and therefore returns the selected formula’s base value.

Synthetic worked examples

For a hypothetical male at 5 ft 10 in (70 in), inches over 5 feet = 10, so IBW = 50.0 + 2.3 × 10 = 73.0 kg. For the female option at the same height, IBW = 45.5 + 23 = 68.5 kg. These demonstrate the formula only and are not recommended targets.

Interpreting the estimate

IBW is a height-and-sex formula reference. It is not actual body weight, BMI, body-fat percentage, nutritional status, or a statement that someone should weigh exactly the result. A difference between actual weight and IBW does not by itself diagnose a health problem.

Common mistakes

  • Entering centimeters while imperial is selected, or combining decimal feet with a separate inches value.
  • Assuming the output is returned in pounds; this implementation reports kilograms.
  • Treating male/female formula constants as an individualized assessment of sex, gender, or physiology.
  • Using the estimate as a mandatory goal, diagnosis, nutrition plan, or medication dose.

Limitations

The Devine formula uses only height and a binary formula constant. It does not account for age, muscle mass, frame size, body composition, ethnicity, pregnancy, disability, fluid status, medical history, or individual goals. Other IBW methods may produce different values.

This calculator is an informational screening and planning estimate, not medical advice, diagnosis, or treatment. A qualified health professional can interpret weight and body-composition information in personal context.

Privacy

The calculation runs in your browser and does not require height or sex selection to be uploaded. Avoid entering identifying information; local history behavior depends on browser and site settings.

FAQ

What is an Ideal Body Weight Calculator?

An ideal body weight calculator estimates a reference weight from sex and height using a published formula. This tool uses the Devine formula and reports kilograms to one decimal place. It is for reference, not a medical prescription.

How is ideal body weight calculated?

This calculator converts height to total inches, finds inches over 5 feet (minimum zero), then applies the Devine formula: male IBW = 50.0 + 2.3 × inches over 5 ft; female IBW = 45.5 + 2.3 × inches over 5 ft. The result is rounded to one decimal place in kg.

What is the Devine formula?

The Devine formula is a classic clinical estimate of ideal body weight from height. For men: 50.0 kg + 2.3 kg per inch over 5 feet. For women: 45.5 kg + 2.3 kg per inch over 5 feet. Five feet equals 60 inches.

How is ideal body weight calculated for men?

For men, IBW = 50.0 kg + 2.3 kg × (total height in inches − 60), using zero additional inches when height is below 5 feet. Example: 5′10″ (70 in) → 50 + 2.3×10 = 73.0 kg.

How is ideal body weight calculated for women?

For women, IBW = 45.5 kg + 2.3 kg × (total height in inches − 60), using zero additional inches when height is below 5 feet. Example: 5′10″ (70 in) → 45.5 + 2.3×10 = 68.5 kg.

Are my height and sex selection uploaded?

The calculation runs in your browser and does not need to upload your inputs to calculate the result. Avoid entering identifying information, and review browser settings if you use local history features.

Can I use centimeters with this calculator?

Yes. Choose metric and enter height in centimeters. The tool converts cm to inches internally before applying the Devine formula.

Is ideal body weight the same as BMI?

No. Ideal body weight from the Devine formula is a height-and-sex estimate in kilograms. BMI uses both height and actual weight in a different equation. They answer different questions.

Is the result a medically recommended weight?

No. This is a population-based formula estimate for reference. It does not account for every individual's muscle mass, age, health conditions, or goals. It is not a prescription or diagnosis.

How accurate is an ideal body weight estimate?

Devine and similar formulas are useful planning references but cannot capture individual variation in frame size, muscle, or health. Treat the result as approximate — not an exact target you must reach.