The ideal weight calculator turns your height, sex, age, and current weight into several outputs. Here is how to interpret each one without over-reading the numbers.

Miller ideal weight (1983)

This formula estimates a population-average healthy weight for your height and sex. It is one of several clinical formulas (Robinson, Devine, and BMI ranges give different answers).

Use it as: a reference point for goal-setting, not a verdict. Athletes, older adults, and people with high muscle mass may sit above Miller ideal while still being healthy.

Body fat percentage range

The calculator shows a general healthy range (roughly 10–20% for men, 18–28% for women per common fitness guidelines). Body fat varies with age, genetics, and activity.

Use it as: context alongside waist measurement and how you feel. Home scales that claim body fat are often inaccurate; DEXA or caliper tests from a professional are more reliable.

Life expectancy estimate

This combines a simplified US life table with a rough penalty for weight above Miller ideal (~0.4 years lost per 5 kg excess, capped). It describes population trends, not your personal forecast.

Do not use it as: a prediction of how long you will live. Genetics, smoking, blood pressure, fitness, and social factors matter far more than this single output.

Fat reserve (energy above ideal)

If you are above ideal weight, the tool estimates how much stored fat energy that excess represents and how many days of sedentary energy it could theoretically supply. The math assumes ~85% of excess weight is fat and uses Mifflin–St Jeor BMR × 1.2.

Use it as: a tangible way to think about gradual loss — not a fasting plan. Rapid weight loss without medical supervision can be harmful.

Reference ranges (pH & temperature)

The bottom panel lists ideal tracking ranges for urine pH, saliva pH, and body temperature with links to MedlinePlus, NIH, and clinical sources. These vary with hydration, meals, and measurement method.

Use them as: trend guides if you already measure these markers. They are not screening tests for disease.

Practical next steps

  1. Compare your current weight to Miller ideal — if the gap is small, focus on habits rather than the number.
  2. Try the BMR/TDEE calculator for daily calorie maintenance estimates.
  3. Log weight weekly and review monthly — see what to track at home.

Last reviewed: June 3, 2026. General wellness information, not medical advice.