CALIPER CAL

CONSISTENCY OVER GUESSWORK

Skinfold estimates,
made clearer.

Caliper Cal helps you locate each measurement site, record repeatable readings, and follow changes over time using established Jackson-Pollock equations.

Google Play, coming soon See how it works

Android first. An iPhone version is planned.

YOUR ESTIMATE

18.7%
Fat mass
31.8 lbLean mass
138.2 lb
No account requiredLocal history3-site and 7-siteMale and female equations

BUILT FOR THE NEXT MEASUREMENT

More useful than a single number.

Body-fat estimates have uncertainty. Caliper Cal focuses on clear technique, repeatable inputs, and trends you can interpret in context.

01

Protocol-aware guidance

Every site includes anatomical landmarks, fold direction, caliper placement, and practical measurement steps.

02

Three readings, one median

Pro supports three rounds at each site and uses the median to reduce the effect of an unusual reading.

03

History that stays yours

Your measurement history is stored on your device. Delete one record, one profile, or everything from Settings.

04

Useful context

See estimated body-fat percentage, fat mass, lean mass, and starting nutrition targets without presenting estimates as diagnoses.

THE METHOD

Measure. Estimate. Compare.

  1. 1

    Choose a protocol

    Select the sex-specific Jackson-Pollock 3-site or 7-site equation that matches the protocol you will measure.

  2. 2

    Locate and mark each site

    Use the same right-side anatomical landmarks every time. Consistent location matters as much as caliper precision.

  3. 3

    Take the fold

    Lift skin and subcutaneous fat away from the muscle, place the caliper about 1 cm below your fingers, and read after pressure settles.

  4. 4

    Follow the trend

    Compare measurements taken with the same method and under similar conditions. Treat the result as an estimate, not an absolute measurement.

MEASUREMENT GUIDANCE

Seven sites. Exact landmarks.

The app provides separate male and female placement instructions where the research protocols differ.

GUIDANCE ARTWORK IN PROGRESSChestDiagonal fold
GUIDANCE ARTWORK IN PROGRESSTricepsVertical fold
GUIDANCE ARTWORK IN PROGRESSSubscapularDiagonal fold
GUIDANCE ARTWORK IN PROGRESSMidaxillaryVertical fold
GUIDANCE ARTWORK IN PROGRESSAbdomenVertical fold
GUIDANCE ARTWORK IN PROGRESSSuprailiacDiagonal fold
GUIDANCE ARTWORK IN PROGRESSThighVertical fold

Final anatomical illustrations will replace these placeholders before publication as measurement guidance.

Read the complete skinfold measurement guide

SOURCE-AWARE BY DESIGN

The research is useful.
The limitations matter.

Caliper Cal uses the generalized Jackson-Pollock body-density equations and the Siri conversion. The original male research included adults ages 18 to 61. The original female research included adults ages 18 to 55 and advised extra care when interpreting results for women over 40.

Accuracy can vary with measurement technique and with age, body-fat level, ethnicity, fat distribution, athletic population, or other differences from the original research samples.

Male equation studyFemale equation studySiri method

START FREE. UPGRADE ONCE.

A straightforward calculator.

FREE

For your own check-ins

  • 3-site and 7-site equations
  • One personal profile
  • Latest three results displayed
  • On-device history retained
  • Measurement guidance

PRO · ONE-TIME PURCHASE

For deeper tracking

  • Everything in Free
  • Multiple client profiles
  • Complete history displayed
  • Three rounds and automatic medians
  • No advertising
Important

Caliper Cal is not a medical device and does not diagnose, treat, cure, or prevent any medical condition. Results are estimates for general fitness and informational purposes. Consult a qualified healthcare professional for medical advice and before making decisions that could affect your health.