We use your phone's GPS and motion sensors to detect your motion and measure your distance. For the Outdoor Walk/Run & Bike mode, we use your phone's GPS, which is usually most accurate in measuring your activity's distance.
For the Indoor Walk/Run, we use your phone's accelerometer or other motion sensors (which may be more or less sensitive) to register your activity like a pedometer and approximate your distance. (This is slightly less accurate.)
We do our best with working with each phone's sensors and we use the same technology that other walk/run/bike tracking app uses. In most cases, we find ours is just as (or even more accurate) than others. But in some instances (i.e., where there is a poor GPS signal, or your phone's motion sensors are more/less sensitive), we may be less accurate.
If you experience consistent and large discrepant inaccuracies, please let us know so that we can fix this. Feedback from our Members are very helpful for us to improve your experience with Charity Miles! To get in touch with us, simply submit a ticket or email us at firstname.lastname@example.org.