Body Fat Calculator Explained for Australians
Estimates body fat percentage using the US Navy tape-measure method. This guide walks through what each input means, the formula behind the answer and a worked example using typical Australian figures. You can follow along in the free Body Fat Calculator.
Why it matters
Australian nutrition labels use kilojoules, alcohol is measured in standard drinks of 10 grams, and health guidance comes from sources such as the NHMRC and Healthdirect. These calculators use common, published formulas as a starting point.
What you need to enter
The calculator asks for 5 inputs. The table shows each one with the example value used later in this guide.
| Input | Example value |
|---|---|
| Sex (1 = male, 0 = female) | 1 |
| Height (cm) | 175 |
| Waist (cm) | 85 |
| Neck (cm) | 38 |
| Hip (cm, women only) | 95 |
The formula
Men use waist, neck and height. Women also use hip. The formula converts these to body density and then body fat.
Worked example
Entering the example values above gives these results:
| Result | Value |
|---|---|
| Estimated body fat | 16.9% |
The headline figure is 16.9% (estimated body fat). Change any input in the calculator and every result updates instantly, so you can test different scenarios side by side.
How the estimated body fat changes with height
The table below keeps every other input at the example value and moves only “Height (cm)” up and down by 10% and 20%. It shows how sensitive the estimated body fat is to that one figure.
| Height (cm) | Estimated body fat |
|---|---|
| 140 | 23.6% |
| 158 | 20% |
| 175 | 16.9% |
| 193 | 14.1% |
| 210 | 11.6% |
At 140 the result is 23.6%; at 210 it is 11.6%. If a small change in this input moves the answer a lot, it is worth double-checking that figure before you rely on the result.
A practical tip
Measure at the same time of day each time, since waist size changes through the day.
Keep going
Before relying on the number, read Body Fat Mistakes Australians Make and How to Avoid Them. You might also find these guides useful:
- How the Ideal Weight Calculator Works (With a Worked Example)
- Water Intake Calculator: Formula, Example and What the Result Means
- Using a Pregnancy Due Date Calculator in Australia: A Step-by-Step Guide
Frequently asked questions
- Are these calculators medical advice?
- No. They provide general information. See your GP or visit healthdirect.gov.au for personal advice.
- Do they work for children?
- No. Adult formulas are used throughout. Children’s growth is assessed differently.
- Where do the formulas come from?
- Each calculator page names the formula used, such as Mifflin-St Jeor for BMR or the US Navy method for body fat.
Run your own numbers in the Body Fat Calculator.
Open the calculatorGeneral information only. Rates and thresholds change, usually on 1 July. Confirm current figures with the ATO or the relevant authority, and get personal advice for decisions about your situation.