Age
Record in yearsThis is a recorded input rather than a body measurement site.
Enter your current age alongside the physical measurements.
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Method guide
Covert Bailey Body Fat Calculator
Uses age and tape measurements, with different limb measurements for men and women.
Calculate
- Accuracy
- ±4-5%Typical error against a reference method
- Equipment
- a soft tape measure
- Measurement count
- 5
Counts include age, weight and height when required.
How to measure
How to take the measurements
Equipment and Good Technique
Use a flexible tape directly against the body where practical. A good circumference reading follows one level path, stays snug without compressing the skin, and is read without twisting the tape. Stand naturally and keep the measured area relaxed rather than changing posture to influence the result.
Required Inputs and Measurement Locations
Measure every item listed for your calculation. Labels show when an input applies only to men or women.
Hips (widest point)
Record in cmAround the widest point of the hips and buttocks.
Stand evenly, circle the fullest point, and check from the side that the tape remains level.
Wrist (smallest point)
Record in cmAround the smallest point of the wrist.
Relax the hand, locate the narrowest circumference, and keep the tape snug without indenting skin.
Waist (at navel)
Men onlyRecord in cmAround the waist at navel level.
Relax the abdomen, keep the tape level, and reuse the same marked waist level.
Forearm (widest point)
Men onlyRecord in cmAround the widest part of the forearm.
Relax the arm, locate its largest circumference, and read without flexing or compressing the skin.
Thigh (widest point)
Women onlyRecord in cmAround the widest point of the thigh.
Relax the leg, locate the maximum circumference, and keep that level for repeat readings.
Calf (widest point)
Women onlyRecord in cmAround the widest part of the calf.
Move the tape along the relaxed calf to find its maximum circumference without compressing the skin.
Measurement Protocol
Follow this sequence
- Measure under repeatable conditions, ideally in the morning before eating or drinking and not immediately after exercise.
- Choose the gender-specific set and record age before taking the physical measurements.
- Work through the listed circumferences in order and use the same side whenever you measure a limb.
- Remove and replace the tape for a second reading at every site rather than reading the same placement twice.
- If two readings disagree, find the landmark again and check the tape level and tension before repeating.
Accuracy and mistakes
How accurate is the Covert Bailey method?
Covert Bailey has an estimated accuracy range of ±4–5% with proper technique. Use that range alongside the method’s practical limitations when deciding whether it suits your measurements.
Who it suits: People who prefer tape measurements and are comfortable locating several limb and torso circumferences.
The trade-off: It avoids calipers, but it asks for more body locations than the simpler tape methods and the required limb sites differ by gender.
What This Method Measures
Uses age and tape measurements, with different limb measurements for men and women.
The Covert Bailey method estimates body fat from age and a set of tape measurements. Everyone records age, wrist and hips. Men also measure waist and forearm; women add thigh and calf. Choosing the correct set and locating each circumference consistently matter as much as reading the tape itself.
This is a circumference method, so there is no skinfold to pinch and no caliper reading to interpret. It needs only a soft tape. A moved tape, a flexed limb or a compressed circumference changes an input before the calculation begins.
- Required inputs
- 5 per calculation, with gender-specific inputs labelled below.
- Equipment
- Prepare a soft tape measure.
Common mistakes that change the result
- Measuring the wrist anywhere other than its smallest circumference.
- Flexing the forearm, thigh or calf while placing the tape.
- Letting the tape climb or dip around the waist or hips.
- Using the wrong gender-specific set of limb measurements.
- Pulling the tape tight enough to change the body outline.
What the estimate means
The calculator turns the recorded inputs into a body fat percentage estimate. For Covert Bailey, the estimated accuracy range is ±4–5% with proper technique. A range is not a promise that one reading is exact.
Treat the result as an estimate. When tracking changes, compare readings collected with the same method and procedure. A changed tool, landmark, body side, timing or operator can make readings less comparable. The number does not diagnose health or replace qualified advice, and formulas with different inputs are not interchangeable.
How this compares to other methods
Ordered by typical error, lowest first. Counts include age, weight and height when required.
| Method | AccuracyTypical error against a reference method | Measurement count | Equipment |
|---|---|---|---|
| Parrillo | ±3-4% | 10 | skinfold calipers, a body-weight scale |
| Jackson & Pollock 7-Site | ±3-4% | 8 | skinfold calipers |
| Jackson & Pollock 4-Site | ±3.5-4.5% | 5 | skinfold calipers |
| Durnin & Womersley | ±3.5-5% | 5 | skinfold calipers |
| Jackson & Pollock 3-Site | ±4-5% | 4 | skinfold calipers |
| Covert BaileyCurrent method | ±4-5% | 5 | a soft tape measure |
| U.S. Navy | ±4-6% | 3 for men · 4 for women | a soft tape measure, a reliable way to measure standing height |
| Modified YMCA | ±4-6% | 2 for men · 5 for women | a soft tape measure, a body-weight scale |
| YMCA | ±5-7% | 2 | a soft tape measure, a body-weight scale |
Where to Go Next
Read the evidence guide
Review the sources and limitations behind Covert Bailey on its paired research page.
View research →Use the calculator app
Take your prepared readings to Body Fat Calculator, select Covert Bailey, and enter the measurements listed for your calculation.
PRO+ includes measurement history and progress tracking in the app. You can also sync app results with Apple Health on iOS when you enable the integration and grant permission.
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