Skinfold Body Fat Calculator

years
mm
Men: Chest (diagonal fold halfway between the nipple and front armpit). Women: Tricep (vertical fold on the back of the upper arm).
mm
Men: Abdomen (vertical fold 2 cm to the right of the navel). Women: Suprailiac (diagonal fold just above the hip bone).
mm
Both sexes: Thigh — vertical fold on the front of the thigh, midway between the knee and the hip.
Health Updated 14 Jun 2026

Skinfold Body Fat Calculator is a health and wellness calculator that helps you calculate skinfold body fat values from your input data. The formula used is: Men (chest, abdomen, thigh):\ndensity = 1.10938 − 0.0008267×S + 0.0000016×S² − 0.0002574×age\n\nWomen (tricep, suprailiac, thigh):\ndensity = 1.0994921 − 0.0009929×S + 0.0000023×S² − 0.0001392×age\n\nBF% = (495 / density) − 450 [Siri equation]\nwhere S = sum of 3 skinfolds (mm). Enter values using the units shown next to each input field (e.g. kg, cm, years).

Rates and fees change frequently. Always confirm the current figures with the official authority before relying on this result.
  • Requires correct measurement technique — best performed by a trained fitness professional.
  • Accuracy decreases significantly with poor measurement technique.
  • Not suitable for very obese individuals where skinfold sites cannot be accurately measured.

Formula

Men (chest, abdomen, thigh): density = 1.10938 − 0.0008267×S + 0.0000016×S² − 0.0002574×age Women (tricep, suprailiac, thigh): density = 1.0994921 − 0.0009929×S + 0.0000023×S² − 0.0001392×age BF% = (495 / density) − 450 [Siri equation] where S = sum of 3 skinfolds (mm)
  • Skinfold Body Fat Calculator gives you a fast estimate using your inputs and updates instantly when you change any value.
  • Formula: Men (chest, abdomen, thigh):\ndensity = 1.10938 − 0.0008267×S + 0.0000016×S² − 0.0002574×age\n\nWomen (tricep, suprailiac, thigh):\ndensity = 1.0994921 − 0.0009929×S + 0.0000023×S² − 0.0001392×age\n\nBF% = (495 / density) − 450 [Siri equation]\nwhere S = sum of 3 skinfolds (mm)
  • Input definitions: • Age: the numeric age used in the calculation • Site 1: the numeric site 1 used in the calculation • Site 2: the numeric site 2 used in the calculation • Site 3 — Thigh: the numeric site 3 — thigh used in the calculation
  • Manual method: write down each input, apply the formula step by step, then compare your manual result with the calculator output.
  • Enter values using the units shown next to each input field (e.g. kg, cm, years).
  • This calculator uses widely accepted health formulas and returns screening estimates only. It does not replace a diagnosis from a qualified healthcare professional.
  • Compare your result with published reference ranges. Values outside the normal range warrant a conversation with your doctor.
  • Practical tip: test a low, medium, and high scenario to understand sensitivity before making decisions.

Example Calculation

Inputs
  • Age: 30 years
  • Site 1: 12 mm
  • Site 2: 20 mm
  • Site 3 — Thigh: 14 mm

Suppose you enter: Age = 30, Site 1 = 12, Site 2 = 20, Site 3 — Thigh = 14. The calculator applies the formula (Men (chest, abdomen, thigh):\ndensity = 1.10938 − 0.0008267×S + 0.0000016×S² − 0.0002574×age\n\nWomen (tricep, suprailiac, thigh):\ndensity = 1.0994921 − 0.0009929×S + 0.0000023×S² − 0.0001392×age\n\nBF% = (495 / density) − 450 [Siri equation]\nwhere S = sum of 3 skinfolds (mm)) and shows all output values below. Change any input field to immediately see how the result changes.

Frequently asked questions

What is the Skinfold Body Fat?
The Skinfold Body Fat Calculator is a health and wellness calculator that helps you calculate skinfold body fat values from your input data. Enter values using the units shown next to each input field (e.g. kg, cm, years).
When should I use this calculator?
Use this calculator whenever you need a quick, accurate result for skinfold body fat values from your input data without working through the arithmetic manually.
What units should I enter?
Enter values using the units shown next to each input field (e.g. kg, cm, years).
How accurate are the results?
This calculator uses widely accepted health formulas and returns screening estimates only. It does not replace a diagnosis from a qualified healthcare professional.
How do I interpret the result?
Compare your result with published reference ranges. Values outside the normal range warrant a conversation with your doctor.
How can I verify the calculation manually?
Use the displayed formula and work through the numbers step by step. If your manual result differs slightly, check rounding and unit conversions first.
Can I use this for planning and budgeting?
Yes. Run best-case, expected, and worst-case inputs to compare outcomes and make safer planning decisions.

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