Common questions and answers about body fat measurement methods, accuracy, and best practices.
Body fat percentage is the total mass of fat divided by total body mass. It includes both essential fat (needed for basic bodily functions) and storage fat. This measurement is more meaningful than BMI for assessing body composition.
Start with the method that matches your tools and comfort level. Tape-based methods are easiest. If you have calipers, the 3-site method is a good balance of accuracy and simplicity. More sites can improve accuracy with proper technique.
Circumference methods only need a soft tape measure. Skinfold methods require calipers. We recommend professional-grade calipers like Harpenden or Lange for best results, though any calipers (like BOZEERA etc) will work.
While some measurements can be done solo, having assistance improves accuracy, especially for hard-to-reach sites like the subscapular. If measuring alone, start with methods that use easily accessible sites.
Measurement frequency depends on your goals. Many people measure every few weeks to spot trends. Consistency matters most, so try to measure at the same time of day.
First, verify your technique and measurement sites. Take multiple measurements at each site and ensure you're using the same locations each time. If problems persist, our support team can help troubleshoot.
Yes! The app is suitable for both personal and professional use. The multiple measurement methods and unit conversion features make it a practical tool for trainers working with clients.
Accuracy depends on the method and your technique. Free methods typically fall around ±4-7%, while PRO+ skinfold methods are typically ±3-5%. All ranges are estimates — real-world accuracy depends heavily on correct site location, consistent technique, caliper quality, and hydration status. Track trends over time rather than treating any single reading as exact.
The Navy method typically falls around ±4-6%, while the YMCA method ranges from ±5-7%. These are circumference-based estimates — less precise than skinfold methods, but useful for tracking trends when measured consistently with the same technique.
Each method uses different measurements and equations optimized for specific populations. Variations can occur due to differences in body type, measurement technique, and the underlying assumptions of each method.
Several factors can impact accuracy: time of day, hydration status, recent exercise, measurement technique, and tool quality. Following our measurement guidelines helps minimize these variables.
Look for consistent readings across repeated measurements and a stable technique at the same sites. If you're unsure, having a professional demonstrate the method can help.
Skinfolds and bioelectrical impedance (BIA) can produce different estimates. BIA is sensitive to hydration and recent intake, while skinfolds can be more consistent when measured correctly.
DEXA is a reference method for body composition. Field methods provide practical, lower-cost estimates that can differ from DEXA, so focus on consistent technique and trends over time.
PRO+ unlocks 6 additional professional measurement methods (including Jackson & Pollock and Durnin & Womersley), decimal precision, measurement history with progress tracking, cloud sync via iCloud or Google Drive, health app integration (Apple Health and Google Health Connect), customisable reminders, and Family Sharing with up to 5 members on iOS.
PRO+ is available as a monthly subscription (£3.99/mo), annual subscription (£19.99/yr — save 58%), or a one-time lifetime purchase (£49.99). All plans include the same features. A free version with 3 basic measurement methods is always available.
Not at all! While we offer monthly (£3.99) and annual (£19.99/yr) plans, we also have a one-time lifetime purchase (£49.99) for those who prefer to pay once. Whichever option you choose, you get the same full PRO+ experience.
Your PRO lifetime purchase is safe — you keep advanced formulas and decimal precision forever, at no additional cost. The new PRO+ features (measurement history, cloud sync, health integration, reminders, and Family Sharing on iOS) are available as an optional upgrade at 50% off as a thank-you for your early support.
Yes! PRO+ includes full measurement history with progress tracking. Save every measurement, view trends over time, and sync your data across devices via iCloud or Google Drive.
The Jackson & Pollock and Durnin & Womersley formulas are based on peer-reviewed research. The U.S. Navy method is based on military technical reports and field protocols. The Parrillo and Covert Bailey methods come from published fitness books rather than peer-reviewed journals. The YMCA methods are based on standard fitness testing protocols. All accuracy ranges are estimates that assume proper measurement technique — consistency matters more than any single reading.
Yes! We provide support for all users. If you have questions about measurements, formulas, or technical issues, contact us at [email protected].