Day stats and active burn
How Trailkeep calculates per-section elevation and active calorie burn, and how to improve accuracy.
Each section in the Trip Planner shows a stats row below the waypoint list. It displays two things side by side: the section's elevation profile and an Active calorie estimate.
Both figures update automatically as you add waypoints, upload a GPX file, or link a gear list to the trip.
Elevation
The elevation row shows the section's total ascent and descent in metres or feet, depending on your distance unit preference.
| Value | Shown when |
|---|---|
| Ascent (▲) | The section has net positive elevation gain |
| Descent (▼) | The section has net negative elevation loss |
How it is calculated:
- When a GPX file is uploaded and waypoints are placed on the route, Trailkeep walks the GPX track between your start point and last waypoint and accumulates vertical gain and loss. A 5-metre noise threshold filters out GPS receiver jitter so the numbers are not artificially inflated.
- When no GPX file is uploaded but waypoints have been placed on the map, Trailkeep uses the terrain altitude stored at each waypoint (fetched from MapTiler when the marker was placed) and sums the positive altitude deltas.
If neither source of elevation data is available, the elevation row is not shown.
Active burn
Active is the estimated energy burned while moving on the trail — the same concept as the active calories shown on a Garmin, Apple Watch, or similar fitness tracker, but calculated in advance from your trip data. Your total daily food intake need will be higher, as it does not include resting metabolism, sleep, or camp activities.
The estimate is calculated using the Pandolf Load Carriage equation — a formula developed from empirical physiological research that accounts for body weight, pack weight, speed, and terrain gradient.
This is a planning estimate, not a sports tracker reading. Individual results vary based on fitness, terrain type, rest stops, and actual pace. Use it to compare sections and plan food resupply, not as a medical measurement.
What goes into the calculation
| Input | Source | Fallback |
|---|---|---|
| Body weight | Your weight set in Settings → Personal details | 70 kg |
| Pack weight | Total weight of the gear list linked to this trip | 12 kg |
| Distance | Sum of waypoint distances for the section (travel segments excluded) | No estimate shown |
| Elevation gain | GPX-derived or waypoint altitude deltas (see above) | 5% average gradient |
Hiking speed is assumed at 1.1 m/s (~4 km/h), a typical loaded trail pace. Time on trail is derived directly from distance at that speed — a longer section means more time moving and therefore more calories burned.
Active burn only appears when at least one non-travel waypoint has a distance entered. Sections with no distance show nothing — an estimate without real distance data is not meaningful.
The app works flexibly with sections
Trailkeep does not assume a section equals one day. You can split a single day into multiple sections, use sections for multi-day legs, or structure your trip any way that suits your planning style. The formula works correctly in all cases because it derives time from actual distance rather than assuming a fixed day length.
How to get accurate numbers
The more data you provide, the closer the estimate gets to reality:
- Enter waypoint distances — open each waypoint and set the distance from the previous stop. This is the most important input — without distance, no estimate is shown.
- Upload a GPX file and place waypoints on the route — this provides precise elevation gain per section rather than the default 5% gradient assumption.
- Link a gear list to the trip — the linked list's total weight is used as the pack weight. See Linking a gear list for details.
- Set your body weight — go to Settings → Personal details and enter your weight. The field accepts kg or lbs and converts automatically.
Trip total
The Summary section at the top of the trip planner shows a total Active figure — the sum of all section estimates. It only appears when at least one section has distance data, using the same condition as the distance chart.
The formula
For those who want the details:
M = 1.5W + 2.0(W+L)(L/W)² + η(W+L)(1.5V² + 0.35VG)Where:
- M — metabolic rate (Watts)
- W — body mass (kg)
- L — pack load (kg)
- V — speed (m/s)
- G — gradient (%)
- η — terrain coefficient (1.0 for trail)
Energy in kcal = M × 0.86 × time on trail in hours.
Pandolf, K.B., Givoni, B., Goldman, R.F. (1977). Predicting energy expenditure with loads while standing or walking very slowly. Journal of Applied Physiology.