Ideal Weight Calculator

Two clinical formulas (Devine and Robinson), a frame-size adjustment, and a BMI-based healthy weight range — all in one result.

Calculate Your Ideal Weight

Gender Frame Size Height

Result will appear here!

Reference estimates only — not a medical diagnosis. Muscle mass, body fat, and bone density all affect what's healthy for you.

What Is an Ideal Weight Calculator?

An Ideal Weight Calculator is a health and fitness tool that provides a reference weight for an individual based on height, gender, and frame size. Rather than giving you one arbitrary number, this calculator shows two established clinical formulas side by side — Devine and Robinson — along with their average and a wider BMI-based range, so you get a fuller picture instead of a single point estimate.

The Two Formulas This Calculator Uses

Both formulas were originally developed for clinical use (drug dosing calculations), not as fitness targets — but they remain widely cited reference points:

Reference sheet: Devine formula men 50 plus 2.3 per inch over 5 feet, women 45.5 plus 2.3 per inch over 5 feet; Robinson formula men 52 plus 1.9 per inch over 5 feet, women 49 plus 1.7 per inch over 5 feet — Devine (1974) and Robinson (1983) — two of the most cited ideal-weight formulas.

Why Frame Size Matters

Two people of identical height can have very different healthy weights depending on bone structure. This calculator applies the commonly cited ±10% adjustment for frame size:

Frame size adjustment: small frame subtracts 10 percent, medium frame no change, large frame adds 10 percent — Small frame −10%, medium frame unchanged, large frame +10%.

For a 5 foot 10 inch male, the Devine formula gives 65.7 kilograms at small frame, 73 kilograms at medium frame, and 80.3 kilograms at large frame — Same height, same formula — a 14.6 kg spread just from frame size.

The BMI-Based Range, for Context

Alongside the two formulas, this calculator shows the weight range that corresponds to a BMI of 18.5–24.9 — the range the World Health Organization classifies as "normal weight":

BMI-based weight range formula: BMI between 18.5 and 24.9 multiplied by height in meters squared — A wider, population-study-based band to check the formula estimates against.

Worked Examples

5'10" male, medium frame:

5 foot 10 inch male medium frame: Devine 73 kg, Robinson 71 kg, average 72 kg, BMI range 58.5 to 78.7 kg — Devine and Robinson differ by 2 kg — both fall inside the BMI range.

5'5" female, medium frame:

5 foot 5 inch female medium frame: Devine 57.0 kg, Robinson 57.5 kg, average 57.3 kg, BMI range 50.4 to 67.9 kg — At this height, the two formulas agree closely.

Why Use an Ideal Weight Calculator?

Set Realistic Fitness Goals – See a reference range instead of a single arbitrary number.
Plan a Weight Loss or Gain Journey – Compare where you are now against a well-known formula range.
Understand the Limits – Frame size and the BMI range both illustrate that "ideal weight" isn't one fixed number.

How to Use the Calculator

Select your gender.
Select your frame size (medium is right for most people).
Enter your height in centimeters, or in total inches.
Click Calculate to see both formula results, their average, and the BMI range.
Use the Clear button to reset and try again.

These formulas are reference estimates, not a medical diagnosis or a target you must hit. None of them account for muscle mass, body fat percentage, or bone density — a muscular, healthy athlete can weigh well above any of these numbers. Talk to a healthcare provider before making significant changes to your diet or exercise routine.

Tips for Maintaining a Healthy Weight

Eat a Balanced Diet – Include lean proteins, whole grains, fruits, and vegetables.
Stay Active – Aim for regular physical activity most days of the week.
Stay Hydrated – Water helps regulate metabolism and curb unnecessary cravings.
Get Enough Sleep – Rest plays a major role in weight management.
Track Trends, Not Single Numbers – Weight fluctuates daily; look at the trend over weeks.

Frequently Asked Questions

What is an Ideal Weight Calculator?

An Ideal Weight Calculator is an online tool that estimates a reference weight for a person based on their height, gender, and body frame size, using established formulas like Devine and Robinson.

How do I use this Ideal Weight Calculator?

Select your gender, enter your height in centimeters or feet and inches, and choose your frame size. The calculator shows the Devine and Robinson formula results, their average, and a BMI-based healthy weight range.

What is frame size and how does it change my result?

Frame size describes bone structure — small, medium, or large. This calculator applies the commonly cited ±10% adjustment: small frame subtracts 10%, large frame adds 10%, and medium frame leaves the formula result unchanged.

Is this calculator accurate?

The Devine and Robinson formulas are widely used reference estimates, not a medical diagnosis. They don't account for muscle mass, body fat percentage, or bone density, which is why this calculator also shows a BMI-based range for wider context.

Why does this calculator show two formulas instead of one?

No single ideal-weight formula is universally correct — each was developed for a different purpose. Showing both Devine and Robinson, plus their average, gives a more honest picture than a single number.

Is the Ideal Weight Calculator free to use?

Yes, it's completely free to use with unlimited calculations and no sign-up required.

Final Thoughts

Your weight is one signal among many when it comes to overall health. Using this Ideal Weight Calculator, you get two formula estimates, a frame-size adjustment, and a BMI-based range — a fuller picture than any single number could give you.