Girths & caliper

Track your body composition with science-backed accuracy.

Girths & Caliper (G&C) is the most precise body fat tracker for fitness enthusiasts, athletes and personal trainers. Measure, log and analyze your progress over time using the same methods used in professional fitness assessment.

SKINFOLD METHODS
Calculate body fat percentage using validated skinfold caliper formulas:
• Jackson-Pollock 7-site (men & women)
• Jackson-Pollock 3-site (men & women)
• Durnin-Womersley 4-site (age-adjusted)
• Sloan 2-site (men & women)
All formulas use the Siri body density equation to compute body fat %, lean mass and fat mass automatically.

GIRTH MEASUREMENTS
Record up to 16 circumferences: chest, waist, hips, neck, biceps (left/right, relaxed and flexed), forearms, thighs, calves, wrists. Track asymmetries between left and right side to identify imbalances.

PROGRESS PHOTOS
Take consistent progress photos with voice-guided body positioning. Compare front, side and back shots over time with a side-by-side view.

AI COACH (Premium)
Get personalized insights from an AI coach powered by Anthropic Claude. The coach analyzes your real measurement deltas and gives you specific, actionable feedback every 4-5 weeks — when body composition changes are actually measurable. Ask follow-up questions through the in-app chat.

CHARTS & TRENDS
Visualize every metric over time. Donut charts for body composition breakdown. Line charts for individual measurements. Bar charts for session-to-session comparisons.

DATA OWNERSHIP
All measurements, photos and analyses are stored locally on your device. We do not collect, sell or track your data. Export everything to CSV anytime.

PRIVACY & SECURITY
• No accounts, no email signup required
• No advertising or third-party tracking
• AI requests are anonymized — no name, no email, no device ID is shared
• All network traffic is encrypted (HTTPS)

WHO IS THIS FOR
• Bodybuilders tracking cut/bulk phases
• Endurance athletes monitoring lean mass changes
• Personal trainers logging client measurements
• Anyone serious about quantifying body composition beyond a scale

SUBSCRIPTION
G&C Standard unlocks the full feature set:
• Monthly: €3.99/month
• Yearly: €34.99/year (save ~27%)

Subscription auto-renews unless cancelled at least 24 hours before the end of the current period.

Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Privacy Policy: see in-app Settings → Privacy

Built by a single developer. No ads, no data harvesting, no dark patterns — just the most accurate body composition tracker we could make.

Questions? app.user.info@icloud.com