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Ideal Weight Calculator

Health

Find your ideal body weight and healthy weight range based on height and gender, using three medical formulas — Robinson, Miller, and Devine.

Reviewed by the thecalcu.com team · Last updated July 3, 2026

Gender
Height
cm
140220
Current Weight
kg
30200

Ideal Weight

—kg

average of Robinson, Miller & Devine formulas

Healthy Weight Range (BMI 18.5–24.9)

—

What is a Ideal Weight?

An ideal weight calculator estimates the body weight considered medically optimal for your height and gender. Rather than using a single formula, this calculator averages three peer-reviewed medical formulas, Robinson (1983), Miller (1983), and Devine (1974), to give a balanced, clinically grounded estimate. It also shows the broader healthy weight range based on BMI 18.5–24.9 and compares your current weight to the ideal, showing how much you might aim to lose or gain.

Ideal weight formulas were originally developed for clinical use, drug dosing, anaesthesia, ICU nutrition calculations, where an accurate weight reference is needed regardless of actual body weight. They have since been widely adopted in fitness and wellness contexts as a general health target.

For Indian adults, ideal weight benchmarks from these formulas are broadly applicable, though research suggests that health risks (particularly metabolic syndrome and cardiovascular disease) may begin at lower BMI thresholds for South Asian populations, around BMI 23 rather than 25. Use the ideal weight alongside the BMI Calculator and Body Fat Calculator for a multi-dimensional view of your health.

Why Use an Ideal Weight Calculator?

Set a concrete weight goal. Vague goals like "I want to be thinner" are harder to work towards than "I want to reach 68 kg." The ideal weight gives you a specific, medically grounded target to build a plan around.

Understand your current position. The weight difference output tells you exactly how far you are from ideal weight, whether that means losing 8 kg, gaining 4 kg, or confirming you are already at a healthy weight. This clarity is the starting point for any nutrition or training programme.

Cross-check BMI-based assessment. BMI gives a range; the ideal weight formulas give a single benchmark. Seeing both side by side, the formula ideal and the BMI range, helps you understand where you sit within the healthy weight spectrum.

Who Should Use This Calculator?

Adults starting a weight management journey who need a concrete target weight to aim for. Knowing the number makes goal-setting in a calorie deficit or surplus much more specific, use alongside the Calorie Calculator to build a timeline.

People recovering from illness or surgery who need to return to a reference healthy weight. The Devine formula in particular is used in clinical and hospital settings for nutritional planning.

Fitness enthusiasts tracking body recomposition who want to understand whether their weight increase reflects muscle gain or fat gain. If you are gaining weight but your body fat percentage is stable or dropping, you are building muscle, the ideal weight formula alone will not capture this.

Parents assessing adult children's health or individuals doing annual wellness checks who want a quick reference alongside other metrics.

What Insights Does the Ideal Weight Calculator Give You?

Ideal Weight (kg) is the average of three medical formulas for your height and gender. This is the single-number benchmark used in clinical nutrition and drug dosing. It typically falls near the middle of the BMI healthy range.

Healthy Range Min and Max show the weight span corresponding to BMI 18.5 (underweight boundary) and 24.9 (overweight boundary) for your height. Being anywhere in this range is associated with normal metabolic health risk.

Weight to Lose / Gain is the gap between your current weight and ideal weight, positive means you are above ideal and that is the weight loss target; negative means you are below and that is the target gain. This is not a medical prescription; use it as a reference alongside professional guidance.

How to use this Ideal Weight calculator

  1. Enter your Height in cm, stand straight without shoes.

  2. Enter your Current Weight in kg, weigh yourself in the morning, before eating, for the most consistent reading.

  3. Select your Gender, the formulas have different constants for males and females reflecting average differences in skeletal frame and muscle distribution.

  4. Read Ideal Weight, the formula-averaged target for your height and gender.

  5. Check your Healthy Range, confirm whether your current weight sits within the BMI 18.5–24.9 window for your height.

  6. Note the Weight Difference, use this as your starting target for a structured nutrition plan. Track progress with the Lean Body Mass Calculator to ensure lost weight comes from fat rather than muscle.

Formula & Methodology

The calculator averages three formulas, all expressed for height in inches above 60 (5 feet):

Robinson (1983):
Male: IBW = 52 + 1.9 × (H − 60) · Female: IBW = 49 + 1.7 × (H − 60)

Miller (1983):
Male: IBW = 56.2 + 1.41 × (H − 60) · Female: IBW = 53.1 + 1.36 × (H − 60)

Devine (1974):
Male: IBW = 50 + 2.3 × (H − 60) · Female: IBW = 45.5 + 2.3 × (H − 60)

Ideal Weight = (Robinson + Miller + Devine) ÷ 3

Healthy Range = BMI 18.5–24.9 × height² (in m²)

Where H = height in inches, converted from cm (1 inch = 2.54 cm)

Worked example:

Female, 165 cm (64.96 inches), current weight 72 kg.

Inches over 5 ft = 64.96 − 60 = 4.96 inches

- Robinson = 49 + 1.7 × 4.96 = 57.4 kg
- Miller = 53.1 + 1.36 × 4.96 = 59.8 kg
- Devine = 45.5 + 2.3 × 4.96 = 56.9 kg
- Ideal Weight = (57.4 + 59.8 + 56.9) ÷ 3 = 58.0 kg
- Healthy Range: 18.5 × 1.65² = 50.3 kg to 24.9 × 1.65² = 67.7 kg
- Weight Difference: 72 − 58 = +14 kg (to lose toward ideal weight)

Frequently Asked Questions

An ideal weight calculator estimates the body weight considered optimal for a given height and gender, based on established medical formulas. It averages three peer-reviewed formulas, Robinson (1983), Miller (1983), and Devine (1974), to produce a balanced estimate. The result represents a target weight associated with lower health risks, not an aesthetic standard, and should be considered alongside other measures like BMI and body fat percentage.
This calculator averages three medical formulas: Robinson (1983), Miller (1983), and Devine (1974). All three were derived from actuarial and clinical data and are expressed as a function of height in inches above 5 feet. Averaging them gives a more robust estimate than any single formula alone, since each was derived from a different population dataset. The healthy weight range is separately derived from the BMI 18.5–24.9 band.
Not exactly. The ideal weight from medical formulas (Robinson, Devine, Miller) typically falls near the middle of the BMI normal range (18.5–24.9), but not at the same value as BMI-derived targets. This calculator shows both, the formula-based ideal weight and the BMI-based healthy range (min to max), so you can see where they align. Use our [BMI Calculator](/bmi-calculator/) for a direct BMI assessment.
For a 170 cm male, the average of the Robinson, Miller, and Devine formulas gives an ideal weight of approximately 66–68 kg. The BMI-based healthy weight range for 170 cm is 53.5–72.0 kg (BMI 18.5–24.9). Indian adults may sit slightly below Western ideal weight benchmarks for the same height due to differences in average body composition, consult your physician for a personalised assessment.
For a 160 cm female, the formula average gives an ideal weight of approximately 53–55 kg. The BMI-based healthy range is 47.4–63.7 kg. Indian women's ideal weight benchmarks are similar to global formulas, though individual differences in muscle mass, bone density, and body frame can shift the appropriate target. Use the [Body Fat Calculator](/body-fat-calculator/) for a body-composition-based view.
Ideal weight is a single number from medical formulas representing the statistically optimal weight for a given height and gender. Healthy weight range is the span of weights corresponding to a BMI between 18.5 and 24.9, a broader band within which health risk is considered normal. You can be healthy anywhere within the range; the 'ideal weight' is simply the midpoint benchmark commonly used in clinical settings for drug dosing, anaesthesia, and nutritional assessment.
For most people, being within the healthy weight range (BMI 18.5–24.9) is sufficient for good metabolic health. Chasing the single 'ideal weight' number is less useful than maintaining a body composition with a healthy body fat percentage and adequate lean mass. Athletes and gym-goers often weigh more than their formula ideal weight because of higher muscle mass, and that is perfectly healthy. Combine weight tracking with [Body Fat Calculator](/body-fat-calculator/) data for a complete picture.
The Robinson, Miller, and Devine formulas were developed in the 1970s–80s from Western population data and are most useful as clinical reference points (used in drug dosing calculations, ICU nutrition, etc.) rather than individual body weight goals. They do not account for muscle mass, bone density, age-related composition changes, or ethnic differences in body composition. For personal fitness goals, body fat percentage and waist-to-height ratio are more meaningful metrics.
This output shows the difference between your current weight and your ideal weight. A positive number means you are above ideal weight and that amount represents the weight to lose. A negative number means you are below ideal weight and would benefit from gaining that amount. This is purely a reference figure, your actual target should be set with a doctor or registered dietitian who can account for your health history and fitness goals.
No. The Robinson, Miller, and Devine formulas are validated for adults, generally those above 18 years and at least 152 cm tall (5 feet). For children and adolescents, ideal weight is assessed using age-and-sex-specific growth charts (WHO or IAP charts for Indian children). This calculator should only be used by adults.
Weight fluctuates by 1–3 kg daily due to water retention, food volume, and hormonal cycles, so daily weigh-ins are not useful. Weigh yourself weekly under consistent conditions, same time of day, same clothing, before eating. Track a rolling 4-week average to observe genuine trends. Recalculate your ideal weight only if your height changes (unlikely as an adult) or if you are comparing progress to a clinical benchmark.
Also known as
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