About this tool
This calculator gives an estimate of ideal body weight (IBW) using the Devine formula, originally developed in 1974 for medication dosing. We also show the WHO healthy weight range based on BMI 18.5 to 24.9, which is a more flexible target that respects body type.
How it works
Devine (women): IBW (kg) = 45.5 + 2.3 x (height in inches - 60)
Healthy range: BMI 18.5 to 24.9 x height (m)²
Enter your height in cm and sex. The calculator converts to inches over 60 (5 feet), applies Devine, and computes a healthy weight range using BMI cutoffs.
How to use the Ideal Body Weight Calculator
The Ideal Body Weight Calculator is a browser-based tool that runs entirely on your device. Inputs you enter never reach a server - all calculations happen client-side in JavaScript. This means:
- Privacy: nothing is logged, sent, or stored by 3Tej. Inputs disappear when you close the tab.
- Speed: results update as you type. No network round trip.
- Offline use: once the page is cached, it works without internet.
- No signup: no account, no email, no rate limits.
Step by step
- Enter your inputs in the form above. Each field is labeled with its unit (currency, percent, kg, etc.) and the expected range.
- Read the result as it updates. The number reflects the formula commonly accepted in Ideal Body Weight-related calculations.
- Adjust to see sensitivity: change one input at a time and watch how the output moves. This is the fastest way to understand which variable matters most.
- Copy or screenshot the result for later reference. The page state persists for the session if your browser allows it.
When you would use this
- Quick estimates: when you need a number now and don't want to open a spreadsheet.
- Sensitivity analysis: testing how a result changes as inputs vary, before committing to a real-world decision.
- Comparison: running the same calculation with different inputs to compare options side by side.
- Learning: building intuition for how the underlying math behaves.
- Documentation: capturing a snapshot of inputs and outputs at a point in time.
Frequently asked questions
What is the Devine formula?
The Devine formula was published in 1974 to standardize medication dosing. For men, ideal weight is 50 kg plus 2.3 kg per inch over 5 feet. For women, it is 45.5 kg plus 2.3 kg per inch over 5 feet.
Is the Devine formula clinically accurate?
Devine was designed for drug dose calculations rather than aesthetic targets. It does not account for muscle mass, frame size, or ethnicity, so use it as a reference only.
What is a healthy weight range?
WHO defines healthy adult weight as a BMI between 18.5 and 24.9 kg/m squared. Multiplying these by your height in meters squared gives a personalized healthy weight range.
Should I aim for ideal body weight?
Use ideal body weight as one reference, but body composition matters more than weight alone. Many athletes weigh more than IBW yet are very healthy due to high muscle mass.
Is the Ideal Body Weight Calculator accurate?
The Ideal Body Weight Calculator applies the standard formula for ideal body weight. Accuracy is limited only by your input precision. For decisions with material consequences, use the result as a starting point and verify with a qualified professional or the relevant official source.
Is the Ideal Body Weight Calculator free?
Yes. 100% free, no signup, no payment, no API key. The site is funded by display ads that appear around the tool but not inside the calculation flow.
Are my inputs saved?
No. Inputs stay in your browser tab. Closing the tab discards them. The site uses Google Analytics for traffic measurement (anonymized) but does not see what you type into the form.
Can I use the Ideal Body Weight Calculator on my phone?
Yes. The tool is responsive and tested on iOS Safari, Android Chrome, and major desktop browsers. Touch targets meet Apple's 44pt and Google's 48dp minimum guidance.
How do I report a bug or suggest improvement to the Ideal Body Weight Calculator?
Email hi@3tej.com with the URL of this page and a description of what you saw vs expected. We typically respond within 72 hours and update calculators when rules or formulas change.
How accurate is the Ideal Body Weight Calculator?
It applies the standard formula. Accuracy is limited only by your input precision. For decisions with material consequences (taxes, medical, legal, structural), use the result as a starting point and verify with a qualified professional in the relevant field.
Is the Ideal Body Weight Calculator free to use?
Yes. 100% free, no signup, no payment, no API key. The site is funded by display ads around the tool but not inside the calculation flow.
Are my inputs saved anywhere?
No. All inputs stay in your browser tab. Closing the tab discards them. The site uses Google Analytics for traffic measurement (anonymized) but the analytics never see what you type into the form.
Does the Ideal Body Weight Calculator work offline?
Yes. Once the page has loaded, it works without internet. The calculation runs in JavaScript on your device.
Can I share results from the Ideal Body Weight Calculator?
Take a screenshot or copy the output. The page doesn't generate shareable URLs for specific calculations - inputs stay in your browser only.
Why are the results different from another ideal body weight tool?
Most likely: different formula assumptions, different default values, different rounding rules, or different applicable rates. Check the methodology if both tools document it. Both can be valid for different scenarios.