Ideal Weight Calculator
This Ideal Weight Calculator estimates a healthy ideal weight range using multiple well-known methods (Devine, Robinson, Miller, and Hamwi) plus a BMI-based healthy range. Because each formula was developed with different assumptions, it’s normal for results to vary—using several methods helps you see a more realistic “zone” instead of one perfect number.
You can enter height in cm or feet + inches, and the results are shown in both kg and lb. If you want to explore other tools, browse All Calculators or the Health & Fitness hub for more body and wellness estimators.
For a calorie-focused next step, you might also check the Basal Metabolic Rate Calculator after you’ve reviewed your suggested ideal zone.
Calculator
Choose your units
Switch between Metric and Imperial. Your values will be converted where possible.
Most “ideal weight” formulas were designed for adults. If you’re under 18, you’ll still get estimates here, but interpret them cautiously and consider professional guidance.
Frame size slightly shifts the final “Suggested Ideal Zone” while keeping the individual method estimates unchanged.
Leave blank if you only want ideal weight estimates. If provided, we’ll place a marker on the BMI gauge.
Results will appear below after you calculate. Your data stays in your browser (no uploads).
Calculating… Building your ideal weight range using multiple formulas.
How the calculation works
This calculator converts your height into total inches (for the IBW methods) and into meters (for the BMI range). Then it computes four classic ideal body weight estimates and aggregates them into a suggested zone.
Variables (with your substituted values after you calculate)
Calculate to see your substituted values here.
Formulas used
Devine (Male): IBW = 50 + 2.3 × (inches − 60)
Devine (Female): IBW = 45.5 + 2.3 × (inches − 60)
Robinson (Male): IBW = 52 + 1.9 × (inches − 60)
Robinson (Female): IBW = 49 + 1.7 × (inches − 60)
Miller (Male): IBW = 56.2 + 1.41 × (inches − 60)
Miller (Female): IBW = 53.1 + 1.36 × (inches − 60)
Hamwi (Male): IBW = 48 + 2.7 × (inches − 60)
Hamwi (Female): IBW = 45.5 + 2.2 × (inches − 60)
BMI Healthy Range:
height_m = height_cm ÷ 100
weight_kg = BMI × (height_m²)
BMI band = 18.5 to 24.9
Step-by-step with your numbers
Calculate to see the full substituted steps here.
Use cases
- Fitness planning: Pick a realistic target band for a cut/bulk phase while keeping performance and recovery in mind.
- Uniform or standard awareness: Compare your estimated zone with formal requirements (where applicable) without treating any single number as destiny.
- Goal setting: Use the zone to define milestones (e.g., “within the band” rather than “one exact weight”).
- Doctor conversation prep: Bring a range-based estimate to discuss context like blood pressure, labs, and body composition.
- Clothing sizing sanity check: Understand how height-based ranges can help explain why two people at the same weight can wear different sizes.
- Recomposition tracking: If your weight stays stable but measurements change, the range mindset helps you avoid overreacting to the scale.
Examples (worked)
These examples show how the calculator reports a suggested ideal zone (aggregated) plus one method estimate. Your results may differ based on height, sex, and frame selection.
Example 1: Adult male, metric
Inputs: Male, Age 30, Height 178 cm, Frame Medium
Output: Suggested Ideal Zone ≈ 63.0–77.5 kg (138.9–170.9 lb)
One method: Devine ≈ 71.0 kg (156.5 lb)
Informational estimate only; athletic builds may sit above BMI-based ranges.
Example 2: Adult female, imperial
Inputs: Female, Age 26, Height 5 ft 4 in, Frame Small
Output: Suggested Ideal Zone ≈ 50.0–61.5 kg (110.2–135.6 lb)
One method: Robinson ≈ 54.4 kg (119.9 lb)
Small frame slightly shifts the combined zone downward and tighter.
Example 3: Older adult male, imperial
Inputs: Male, Age 62, Height 6 ft 1 in, Frame Large
Output: Suggested Ideal Zone ≈ 74.0–90.0 kg (163.1–198.4 lb)
One method: Hamwi ≈ 79.1 kg (174.4 lb)
In older adults, functional strength and medical context often matter more than a single target weight.
Common Mistakes
- Mixing units: entering feet/inches but thinking it’s centimeters (or vice versa) can radically distort results.
- Invalid inches: typing 12–15 inches instead of converting to an extra foot (inches must be 0–11).
- Chasing one “perfect” number: ideal weight is better interpreted as a zone, not a single target.
- Ignoring body composition: athletes and lifters may be “healthy” above BMI-based ranges due to muscle mass.
- Rounding height too aggressively: small height changes alter BMI and IBW math—measure carefully, especially if you’re near a boundary.
- Applying adult formulas to teens: growth patterns differ; use extra caution if under 18.
Quick Tips
- Measure height correctly: stand tall, shoes off, and re-check once or twice for consistency.
- Use the range mindset: aim for the zone, then adjust based on energy, performance, and health markers.
- Track trends, not one-day readings: body weight fluctuates—weekly averages are usually more meaningful.
- Pair with measurements: waist, hips, and strength metrics help contextualize scale changes.
- Choose a frame size honestly: if unsure, keep Medium; it’s designed as a neutral default.
- Use multiple methods: if one formula seems “off,” compare across methods instead of discarding everything.
Accuracy, Privacy & Notes
Accuracy & method note: Runs locally in your browser using established ideal body weight formulas (Devine, Robinson, Miller, Hamwi) and a BMI-based healthy range. Results are informational and not medical advice.
Rounding / precision policy: Internal calculations keep higher precision; displayed results are rounded to 1 decimal for kg and lb to balance clarity and consistency.
Privacy-first: No data is sent anywhere. Inputs and outputs stay on your device.
Last Updated: January 29, 2026
Sources & References (concepts)
- Devine ideal body weight formula
- Robinson ideal body weight formula
- Miller ideal body weight formula
- Hamwi ideal body weight formula
- BMI healthy range concept (18.5–24.9)
FAQ
These formulas were created at different times and with different reference assumptions. They use slightly different base weights at 5 feet and different “per inch” adjustments above (or below) 5 feet. That’s why two methods can disagree by several kilograms or pounds for the same height. Instead of picking one as “the truth,” it’s more practical to view them together and use an aggregated range as a starting point—especially if your body composition or training background differs from the populations these formulas historically referenced.
The Suggested Ideal Zone is an aggregated range built from multiple ideal body weight (IBW) methods. In this calculator, we compute Devine, Robinson, Miller, and Hamwi, then take the minimum and maximum across those estimates. That creates a realistic “method band” rather than a single target. We then apply a small, transparent adjustment based on your selected frame size to nudge the zone slightly. It’s not a diagnosis; it’s a practical estimate you can compare with your goals and other health indicators.
BMI is calculated as weight divided by height squared, so we can solve it the other way around to get a weight range for a given height. We convert your height into meters, then compute weight = BMI × (height_m²). This calculator uses the conventional “healthy” BMI band of 18.5 to 24.9 and converts the resulting weights into both kilograms and pounds. BMI is useful for context, but it does not measure muscle mass, bone density, or fat distribution—so it should be interpreted alongside other information.
Frame size can matter, but it’s usually a subtle influence rather than a dramatic one. Two people of the same height might differ in bone structure and shoulder/hip
width, which can change what “comfortable and sustainable” weight looks like. Because frame size is hard to measure perfectly without specific methods, this calculator uses it as a gentle adjustment to the combined zone—not to rewrite each formula. If you’re unsure, keep the default Medium. If you consistently feel best and perform well at the higher or lower edge of the zone, that’s often a better indicator than forcing your body toward one exact number.
It can be useful, but athletes should interpret results differently. Classic IBW formulas and BMI ranges rely on height and do not directly measure muscle mass, body fat percentage, or performance needs. If you lift, sprint, or train regularly, a higher body weight may still be healthy because muscle is denser than fat. Treat the “Suggested Ideal Zone” as a reference band, then compare it with waist measurements, strength, endurance, recovery, and clinician feedback. In many athletic cases, the BMI-based band may look “too low” despite excellent health markers.
Use extra caution. Many ideal body weight formulas were designed with adult assumptions and don’t account for growth, puberty timing, or pediatric percentiles. This calculator will still compute estimates if you enter an age under 18, but it adds a caution note because the “right” weight for teens is often better assessed with age- and sex-specific growth charts and a healthcare professional’s context. If you’re a teen (or a parent/guardian), focus more on healthy habits, strength, and wellbeing than on hitting a single target number.
BMI is included because it provides a familiar reference range that many people recognize and clinicians often discuss. It’s quick to compute from height and weight and can be useful at the population level. However, BMI doesn’t distinguish muscle from fat or reflect where weight is carried, so individuals can fall outside the “healthy” band and still be healthy. In this calculator, the BMI band is a context layer: compare it with the multiple IBW method outputs and your combined zone, then interpret the full picture rather than relying on BMI alone.
There isn’t one universal “best point” inside the range. Many people do well near the middle, but your ideal spot depends on your goals, training, appetite, and health indicators. If you prioritize endurance or speed, you might feel better closer to the lower-middle. If you prioritize strength or muscle gain, you may sit comfortably in the upper-middle. If you have medical considerations, discuss targets with a clinician. The range is meant to be flexible—use it to guide decisions, not to police normal body variability.
They can still compute, but caution increases at the extremes. The formulas scale from a 5-foot reference point by adding or subtracting a per-inch value, which may not represent real-world diversity equally across all body types. For heights below 5 feet, the “inches − 60” term becomes negative, reducing the estimate; that may be reasonable for some people but can also feel too low if you have higher muscle mass or different proportions. For very tall heights, compare multiple methods and use the aggregated zone rather than trusting one formula in isolation.
Showing both units reduces errors and makes the results easier to compare across different references. Many formulas were popularized in settings that used imperial height inputs (feet/inches) while reporting the final ideal body weight in kilograms. Meanwhile, everyday tracking might be in pounds depending on your region. By displaying both kg and lb together, you can sanity-check numbers and avoid common mix-ups like interpreting a kilogram figure as pounds. Internally, the calculator keeps higher precision and rounds only for display to keep the outputs consistent and readable.
No—this is an informational calculator that provides estimates based on established formulas and a BMI reference band. It does not diagnose health conditions, and it cannot account for individual factors like body fat percentage, muscle distribution, medical history, medications, pregnancy status, or disease risk. Use the results as a starting point for understanding how height-based estimates are commonly computed, then interpret them with context. If you’re making health decisions or have concerns about weight changes, consider discussing goals with a qualified healthcare professional who can evaluate your full situation.
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