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Skinfold Body Fat Calculator

Calipers pinch the skin to measure the fat layer beneath it. The sum of three sites estimates whole-body density, and density converts to a body fat percentage. Men and women store fat differently, so each has its own coefficients.

Your numbers

Body fat

15.65%

Fat mass

10.95kg

Lean mass

59.05kg

Formula

Body fat = 495 ÷ (1.10938 − 0.0008267 × Skinfold total + 0.0000016 × Skinfold total² − 0.0002574 × Age) − 450

Men measure chest, abdomen and thigh; women triceps, suprailiac and thigh. Consistency of site and pressure matters more than the absolute number, so track the change rather than the value.

What to enter

InputDefaultAccepted range
Skinfold total (mm)The three caliper readings added together.500 and up
Age (yr)Age in completed years — it shifts by one depending on the birthday.350 ~ 100
Sex (M1 / F0)Where the formula splits by sex — enter 1 for male, 0 for female.10 ~ 1
Weight (kg) (kg)The second weight you are comparing against.700 and up

Step by step

FormulaBody fat = 495 ÷ (1.10938 − 0.0008267 × Skinfold total + 0.0000016 × Skinfold total² − 0.0002574 × Age) − 450
With the default numbersBody fat = 495 ÷ (1.10938 − 0.0008267 × 50 + 0.0000016 × 50² − 0.0002574 × 35) − 450
AnswerBody fat = 15.65 %

Quick reference table

Results when only Skinfold total (mm) changes and everything else stays put.

Skinfold total (mm)Body fat (%)Fat mass (kg)Lean mass (kg)
258.035.6264.38
37.511.928.3461.66
5015.6510.9559.05
7522.6115.8354.17
10028.8620.249.8

What each result means

ResultAt default values
Body fat (%)The share of body weight that is fat.15.65
Fat mass (kg)How much of your weight is fat, in kilograms.10.95
Lean mass (kg)Everything that is not fat — muscle, bone, water.59.05

Common mistakes

Men measure chest, abdomen and thigh; women triceps, suprailiac and thigh. Consistency of site and pressure matters more than the absolute number, so track the change rather than the value.

Glossary

Skinfold total
The three caliper readings added together.
Age
Age in completed years — it shifts by one depending on the birthday.
Sex (M1 / F0)
Where the formula splits by sex — enter 1 for male, 0 for female.
Weight (kg)
The second weight you are comparing against.
Body fat
The share of body weight that is fat.
Fat mass
How much of your weight is fat, in kilograms.
Lean mass
Everything that is not fat — muscle, bone, water.

Frequently asked questions

Q. How is Skinfold Body Fat Calculator calculated?

Body fat = 495 ÷ (1.10938 − 0.0008267 × Skinfold total + 0.0000016 × Skinfold total² − 0.0002574 × Age) − 450 — Calipers pinch the skin to measure the fat layer beneath it. The sum of three sites estimates whole-body density, and density converts to a body fat percentage. Men and women store fat differently, so each has its own coefficients.

Q. Can you walk through an example?

With Skinfold total 50mm, Age 35yr, Sex (M1 / F0) 1, Weight (kg) 70kg, the answer is Body fat 15.65%.

Q. What do I need to enter?

Enter Skinfold total, Age, Sex (M1 / F0), Weight (kg). The result recalculates as you type, and an empty box counts as zero.

Q. How much does the answer move if I change a number?

Changing only Skinfold total (mm) moves the answer to Skinfold total (mm) 25 → Body fat (%) 8.03 and Skinfold total (mm) 100 → Body fat (%) 28.86. The table below lays out five steps.

Q. How are the numbers rounded?

Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.

Q. Anything to watch out for?

Men measure chest, abdomen and thigh; women triceps, suprailiac and thigh. Consistency of site and pressure matters more than the absolute number, so track the change rather than the value.

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