Understand trip distances

While a trip is active, MileLedger collects GPS coordinate samples from Core Location. Each sample includes a horizontal accuracy value (in metres).

Samples with poor accuracy are filtered out before distance is computed. The remaining samples are chained together and the distances between consecutive points are summed to produce the total trip distance.

GPS distance is the sum of filtered coordinate samples along the path MileLedger recorded. On curved roads or with sparse samples, that total can differ from a map-routing estimate or your odometer. Incomplete or low-accuracy sessions are flagged for review instead of inventing miles.

If too many samples were filtered out due to low accuracy, MileLedger cannot confidently report a distance. The trip is saved with a **Needs Review** flag and its distance shown as uncertain.

This happens in underground car parks, tunnels, dense urban canyons, or any environment that blocks GPS signals.

MileLedger will never invent or extrapolate mileage. A flagged trip may show a shorter-than-actual distance, not a longer one.

Open the drive, tap **Edit**, and update the **Distance** field. Your manually entered value overrides the GPS calculation and is marked as a manual override in the trip detail.

The original GPS route remains intact and visible on the map—only the reported distance changes.

Trips shorter than approximately **0.5 miles (804.672 m)** are saved with a **Short Trip** flag. They are excluded from most mileage report totals by default.