Calculator Comparison

BMI Calculator vs Ideal Weight Calculator

Not sure which calculator to use? Here's a side-by-side comparison of the BMI Calculator and Ideal Weight Calculator to help you pick the right one for your needs.

BMI Calculator

Health & Fitness

Calculate your Body Mass Index (BMI) to determine if you're at a healthy weight based on your height and weight.

What you enter

Weight (lbs)
Height (feet)
Height (inches)

What you get

Your BMI(primary)
Weight Category
Healthy Weight Range

Use BMI Calculator

Ideal Weight Calculator

Health & Fitness

Find your ideal body weight range using multiple scientifically validated formulas based on your height and gender.

What you enter

Gender
Height (feet)
Height (inches)
Body Frame

What you get

Ideal Weight (Robinson)(primary)
Ideal Weight (Miller)
Ideal Weight (Hamwi)
Healthy BMI Range

Use Ideal Weight Calculator

Key Differences

Feature	BMI Calculator	Ideal Weight Calculator
Category	Health & Fitness	Health & Fitness
Inputs	3 required fields	4 required fields
Outputs	3 results	4 results
Chart	No chart	No chart
FAQs	6 answered	6 answered

Input Comparison

Shared Inputs

Height (feet)
Height (inches)

Only in BMI Calculator

Weight (lbs)

Only in Ideal Weight Calculator

Gender
Body Frame

Which Calculator Should You Use?

Use the BMI Calculator if you need to:

Calculate your bmi
When you know your weight (lbs) and height (feet)

Use the Ideal Weight Calculator if you need to:

Calculate ideal weight (robinson)
When you know your gender and height (feet)

Frequently Asked Questions

What is a healthy BMI range?

For adults, BMI under 18.5 is underweight, 18.5–24.9 is normal weight, 25–29.9 is overweight, and 30 or above is obese. These thresholds apply to most adults but may differ for older adults, children, and some ethnic groups where health risks occur at lower BMI values.

Is BMI accurate for athletes?

BMI is a rough population-level screening tool, not a precise individual measure. Muscular athletes often have a high BMI despite low body fat because muscle weighs more than fat. A 200 lb bodybuilder and a 200 lb sedentary person have the same BMI, but very different health profiles.

How is ideal weight calculated?

This calculator uses several established formulas: Devine (1974), Robinson (1983), Miller (1983), and Hamwi (1964). Each produces slightly different results because they were developed from different population studies. The displayed range covers all four estimates, reflecting the genuine uncertainty in what 'ideal' means for any individual.

Does body frame affect ideal weight?

Yes. Someone with a large bone structure naturally weighs more than a small-framed person of identical height. A rough way to assess frame size: wrap your thumb and middle finger around your wrist — if they overlap, you have a small frame; if they just touch, medium; if they don't reach, large. Adjust target weight expectations accordingly.

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Bottom Line

Choose the BMI Calculator if you need to calculate your bmi. Use the Ideal Weight Calculator if you need to calculate ideal weight (robinson). Both calculators are free and require no sign-up.

Use BMI Calculator Use Ideal Weight Calculator

Feature

BMI Calculator

Ideal Weight Calculator