Body Fat Calculator – Estimate Body Fat % from BMI (Free)
Estimate body fat percentage from weight, height, age, and sex using a BMI-based regression model—useful for trends, not a lab replacement.
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Quick answer
Body Fat Calculator is a free online health calculator on CalcSuite Pro. It implements: Body fat % ≈ 1.20×BMI + 0.23×age − 10.8×(male=1) − 5.4 (Deurenberg-style estimate; not DEXA).. You enter sex, age, height, weight, then get a computed result in your browser.
It is built for quick checks, homework verification, and scenario comparisons when you already understand the underlying model and units. Outputs are educational estimates only—not medical diagnosis or treatment advice.
Invalid or missing inputs show an error instead of a misleading number; compare multiple runs when you stress-test assumptions.
Years
Centimeters
Kilograms
Result
Enter values and click calculate.
Formula
Body fat % ≈ 1.20×BMI + 0.23×age − 10.8×(male=1) − 5.4 (Deurenberg-style estimate; not DEXA).
Explanation
Body Fat Calculator computes results using the formula Body fat % ≈ 1.20×BMI + 0.23×age − 10.8×(male=1) − 5.4 (Deurenberg-style estimate; not DEXA). from your input values: sex, age, height, and weight. Entering each field returns a numerical answer based on that exact equation, so the page is a faster, less error-prone alternative to running the math by hand.
It is built for personal wellness tracking and routine planning, estimating body metrics before fitness decisions, and building healthier goals with measurable numbers. People typically open this calculator when they need a quick, repeatable answer they can check in seconds—students confirming a homework number, professionals validating a real-world figure, or anyone running a what-if scenario before making a decision.
Read the result alongside the formula on this page so each input's effect is transparent, then re-run with adjusted values to see how the answer changes. If anything looks off, double-check unit consistency in your inputs—mixing percent values with decimals or months with years is the most common source of an unexpected result.
How to Use
- Enter or choose Sex (Female / Male), Age, Height, and Weight as indicated.
- Use the units shown under each field (for example kg, m, cm, years).
- Click Calculate to run the Body fat % ≈ 1.20×BMI + 0.23×age − 10.8×(male=1) − 5.4 (Deurenberg-style estimate; not DEXA). formula.
- Read the result and compare with alternate values if you want scenario-based planning.
Example
Sample inputs: Sex = woman, Age = 28, Height = 168, Weight = 65
Calculated result: 28.7000
You can replace these values with your own numbers to calculate a real-world result instantly.
FAQ
What is a body fat calculator?
Body Fat Calculator helps you apply the formula "Body fat % ≈ 1.20×BMI + 0.23×age − 10.8×(male=1) − 5.4 (Deurenberg-style estimate; not DEXA)." quickly using your own values.
When should I use this body fat calculator?
Use it when you need quick and repeatable health calculations without manual errors.
How accurate are the results?
Results are formula-based and depend on entering correct values with the right units.
Why am I seeing an invalid input message?
One or more required values are missing, non-numeric, or caused a divide-by-zero condition.
Is this calculator free to use?
Yes. You can use this calculator online for free.
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