Ideal Weight Calculator

Calculate Ideal Weight

cm

Estimated Ideal Weight

70.5 kg

Average of 3 formulas

Healthy Range

68.9 kg – 72.0 kg

See how this is calculated

How This Calculation Works

This calculator averages three long-established medical formulas — Devine, Robinson, and Hamwi — each originally developed to estimate a reasonable body weight for medication dosing and clinical reference, not as a fitness or aesthetic target. All three use a similar structure: a base weight for 5 feet (152 cm) of height, plus an additional amount for every inch above that.

Because the three formulas produce slightly different results, the calculator shows both the average (a single reference number) and the full range spanning the lowest to highest of the three estimates — giving you a healthy range rather than a single rigid target.

These formulas were developed decades ago primarily using data from specific populations, so they don't account for individual differences in frame size, muscle mass, or body composition. They're best used as a rough reference point, not a precise personal goal.

Common Mistakes to Avoid

  • Treating the result as a strict target. These formulas produce a population-level reference range, not a personalized prescription. Frame size, muscle mass, and individual health context all matter more than hitting an exact number.
  • Ignoring muscle mass. A muscular, athletic person will often weigh more than these formulas suggest while still being lean and healthy — the formulas don't distinguish muscle from fat.
  • Comparing to BMI without context. Ideal weight formulas and BMI categories don't always agree exactly, since they were developed independently. Use both as general reference points rather than expecting them to match perfectly.
  • Applying it to children, teens, or older adults without adjustment. These formulas were developed for and are most applicable to non-elderly adults. Growth-related and age-related weight guidance for children, teens, and older adults should come from age-appropriate charts and a healthcare provider.

Worked Example

Scenario: A man who is 175 cm tall (about 68.9 inches, or 8.9 inches over 5 feet).

Devine: 50 + (2.3 × 8.9) ≈ 70.5 kg.

Robinson: 52 + (1.9 × 8.9) ≈ 68.9 kg.

Hamwi: 48 + (2.7 × 8.9) ≈ 72.0 kg.

Result: Average ≈ 70.5 kg, with a range of about 68.9–72.0 kg across the three formulas.

Frequently Asked Questions

Which ideal weight formula is most accurate?
None is definitively "most accurate" — they were developed at different times using different reference populations, and each has known limitations. Using the average of multiple formulas, as this calculator does, tends to smooth out the quirks of any single formula and gives a more balanced reference range.
Why does my ideal weight range seem low compared to how I feel healthy?
These formulas don't account for muscle mass, so athletic or muscular individuals often naturally weigh more than the calculated range while still being lean and healthy. If you exercise regularly and have good body composition, don't treat the number as a strict target.
Is ideal weight the same as a healthy BMI weight?
They're related but calculated differently, and can give slightly different results for the same height. BMI-based healthy weight ranges use the 18.5-24.9 BMI category, while these formulas use their own historical reference equations — both are useful general guides rather than precise individual targets.
Should I use this to set a weight loss or gain goal?
It's a reasonable starting reference point, but a good goal should also consider your body composition, health markers, energy levels, and how you feel — not just a number from a formula. Consulting a healthcare provider or registered dietitian can help set a more personalized target.

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