This tool estimates healthy weight targets from height and reports results in kilograms and pounds. It computes a WHO/CDC healthy-BMI weight range, a user-chosen target-BMI weight, and four classic “ideal body weight” (IBW) formulas (Hamwi, Devine, Robinson, Miller), plus their average. It accepts height in cm or ft/in and guides you step by step.

Features

  • Metric & Imperial input with automatic conversion.
  • Healthy BMI weight range using 18.5–24.9 kg/m².
  • Custom target BMI (default 22.0) → single “target weight.”
  • Four IBW formulas (Hamwi, Devine, Robinson, Miller) and their mean.
  • Dual-units output: kg with lb in parentheses.

How to use

  1. Select Body profile (male or female). Several formulas use sex-specific constants.
  2. Choose Unit system. Enter height in cm or in ft + in.
  3. (Optional) Set Target BMI (10–30). Leave blank to use 22.0.
  4. Click Calculate. Review the BMI weight range, your target-BMI weight, each formula’s estimate, and the average across formulas.

Methods and formulas

A) BMI-based weights

Definition. BMI = weight_kg / height_m². Public-health ranges for adults: Healthy Weight = 18.5–24.9 kg/m².

  • Healthy range mapped to weight: W_low = 18.5 × h², W_high = 24.9 × h².
  • Target-BMI weight: choose a BMI (default 22.0), then W_target = BMI_target × h².

Establishes a medically recognized “healthy” interval anchored only to height. Does not account for fat distribution or lean mass.

B) Classic IBW formulas (adult, height-only)

These formulas originated in clinical dosing and bedside estimation. Inputs are adult height and sex; outputs are kg. They linearly add weight per inch above 5 ft (60 in). For heights below 60 in they extrapolate downward.

1) Hamwi (1964)

  • Male: W_kg = 48.0 + 2.7 × (in − 60)
  • Female: W_kg = 45.5 + 2.2 × (in − 60)

Originally presented in a clinical context; some variants include ±10% adjustments for “frame size.”

2) Devine (1974)

  • Male: W_kg = 50.0 + 2.3 × (in − 60)
  • Female: W_kg = 45.5 + 2.3 × (in − 60)

Widely used for drug dosing; often cited as a modern baseline IBW equation.

3) Robinson et al. (1983)

  • Male: W_kg = 52.0 + 1.9 × (in − 60)
  • Female: W_kg = 49.0 + 1.7 × (in − 60)

A refinement using empirical data; reduces the per-inch add-on versus earlier formulas.

4) Miller et al. (1983)

  • Male: W_kg = 56.2 + 1.41 × (in − 60)
  • Female: W_kg = 53.1 + 1.36 × (in − 60)

Another pharmacotherapy-oriented equation; smallest per-inch increments among the four.

Average of formulas. The tool reports the simple mean of Hamwi, Devine, Robinson, and Miller to provide one practical midpoint.

Units and conversions used

  • Height: 1 in = 2.54 cm; 1 ft = 12 in; h_m = h_cm / 100.
  • Weight: 1 kg = 2.2046226218 lb.

Interpreting results

  • BMI range supplies normative public-health bounds for adults at a given height.
  • Target-BMI weight gives one actionable point inside the healthy range. Raise it for muscular builds, lower it for endurance-lean builds.
  • IBW formulas are heuristics from clinical dosing. They do not encode age, ethnicity, body fat %, or skeletal frame unless a frame adjustment is explicitly added.
  • Averages smooth differences between formulas and are convenient for planning, not prescriptive.

Examples

Example A. Male, 175 cm (1.75 m). BMI 18.5–24.9 → 56.6–76.2 kg. Target BMI 22.0 → 67.4 kg. IBW: Hamwi ≈ 68.0; Devine ≈ 70.5; Robinson ≈ 67.2; Miller ≈ 69.1 → Average ≈ 68.7 kg (151.5 lb).

Example B. Female, 5 ft 6 in (66 in = 1.676 m). BMI 18.5–24.9 → 52.0–70.0 kg. Target BMI 22.0 → 61.9 kg. IBW: Hamwi ≈ 59.7; Devine ≈ 59.3; Robinson ≈ 58.2; Miller ≈ 61.3 → Average ≈ 59.6 kg (131.4 lb).

Ideal Weight Calculator For Men And Women

Strengths and limits

  • Strengths: simple inputs; clear ranges; widely recognized BMI cutoffs; multiple formula snapshots for context.
  • Limits: height-only models miss body fat %, muscle mass, bone density, age-related shifts, and fat distribution. Very short or very tall heights require extrapolation.

When to prefer other metrics

  • Athletes or lifters: add waist-to-height ratio, body-fat assessment, or DXA where possible.
  • Older adults or clinical decisions: combine with clinical judgement; BMI cutoffs may be interpreted differently with age or comorbidities.

Sources

What is your perfect body weight? Would you like to see any other calculator here? Let us know in the comments below!

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