Inputs
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Example Data Table
| Route | Distance | Gain | Hours | Terrain | Pack |
|---|---|---|---|---|---|
| Valley Loop | 8 km | 200 m | 2.0 | Uneven trail | 5 kg |
| Ridge Push | 12 km | 800 m | 4.0 | Rocky/rooted | 8 kg |
| Snow Pass | 10 km | 600 m | 3.5 | Snow/sand | 10 kg |
Formulas Used
MET-based method: Base METs chosen by speed and terrain. Load, altitude, heat, wind, and downhill factors adjust MET.
Calories = MET × weight(kg) × duration(h).
- Speed = distance / duration; units auto-convert.
- Terrain factor multiplies METs: 1.00–1.30.
- Load factor: +0.10 MET per 5 kg carried.
- Altitude factor: +3% MET per 1000 m average altitude.
- Temperature/humidity: up to ±15% adjustment combined.
- Wind: +2% per m/s headwind; −1% per m/s tailwind (caps apply).
- Downhill: moderate negative grades reduce cost; steep add braking cost.
- Rest factor (optional): +5% energy for short stops.
ACSM walking with grade: VO₂ (ml/kg/min) = 0.1·v + 1.8·v·grade + 3.5, where v is speed (m/min) and grade is decimal.
kcal/min ≈ VO₂ × weight(kg) / 1000 × 5. Total calories sum over duration.
Heart-rate option: If enabled with average HR, uses gender-specific equations to estimate calories from HR, weight, and age over minutes.
These equations are educational estimates and not medical advice.
How to Use This Calculator
- Pick units, enter body and pack weight.
- Enter distance, duration, elevation up/down, and typical grades.
- Set weather, altitude, terrain, and wind for better accuracy.
- Optionally import a GPX track to auto-fill distance and gain.
- Enable heart-rate method if you have average HR data.
- Press calculate to view energy, rates, and fueling guidance.
- Export results as CSV or PDF for trip planning.
Reference Data & Examples
1) Typical METs by Terrain and Speed
| Speed (km/h) | Paved | Uneven | Rocky/Rooted | Snow/Sand |
|---|---|---|---|---|
| <3.0 | 3.0 | 3.3 | 3.6 | 3.9 |
| 3.0–3.9 | 3.5 | 3.9 | 4.2 | 4.6 |
| 4.0–4.9 | 4.3 | 4.7 | 5.2 | 5.6 |
| 5.0–5.9 | 5.3 | 5.8 | 6.4 | 6.9 |
| 6.0–6.9 | 6.5 | 7.2 | 7.8 | 8.5 |
| ≥7.0 | 7.5 | 8.3 | 9.0 | 9.8 |
2) Load Adjustment Table
Approximate MET adders for carried load. Values stack with terrain and grade.
| Pack (kg) | + MET | Pack (lb) |
|---|---|---|
| 0–4.9 | +0.00 | 0–11 |
| 5–9.9 | +0.10 | 11–22 |
| 10–14.9 | +0.20 | 22–33 |
| 15–19.9 | +0.30 | 33–44 |
| ≥20 | +0.40 | ≥44 |
3) Altitude Adjustment Guide
| Avg Altitude (m) | MET Multiplier | Note |
|---|---|---|
| 0–999 | ×1.00 | Sea level baseline |
| 1000–1999 | ×1.03 | Mild increase |
| 2000–2999 | ×1.06 | Noticeable effect |
| 3000–3999 | ×1.09 | Acclimatization advised |
| ≥4000 | ×1.12 | High-altitude caution |
4) Fueling & Hydration Targets by Heat
| Temp (°C) | Suggested Hydration (L/h) | Carbs Target (g/h) |
|---|---|---|
| ≤10 | 0.35–0.50 | 30–45 |
| 11–20 | 0.45–0.60 | 40–60 |
| 21–28 | 0.60–0.90 | 50–75 |
| ≥29 | 0.90–1.20 | 60–90 |
5) Example Scenarios
| Scenario | Inputs | Computed |
|---|---|---|
| Day hike | 70 kg, 5 kg pack, 10 km, 3 h, 300 m gain | ~650–800 kcal total; ~220–270 kcal/h |
| Rocky ascent | 80 kg, 10 kg pack, 12 km, 5 h, 900 m gain | ~1500–1900 kcal total; ~300–380 kcal/h |
| Hot desert loop | 68 kg, 6 kg pack, 8 km, 2.5 h, 150 m gain, 34°C | ~600–800 kcal; hydration 0.9–1.2 L/h; 60–90 g/h |
| Snowy trek | 75 kg, 12 kg pack, 10 km, 4 h, 600 m gain, snow | ~1000–1300 kcal; terrain factor elevates cost |
FAQs
1) How accurate are these calorie estimates?
They are educated estimates based on validated equations and assumptions. Individual efficiency varies with fitness, technique, altitude acclimatization, and conditions. Use results for planning, not medical decisions.
2) Which model should I choose?
Use MET-based for quick planning across terrains. Choose the VO₂ grade model when you know average grade and want steeper terrain sensitivity. Results typically converge for moderate hikes with consistent pacing.
3) What does the heart-rate option do?
It estimates calories from average heart rate, weight, age, and sex. It can better reflect your physiology. Calibrate with a reliable strap sensor and steady-state efforts for best results.
4) Can I import GPX from my watch?
Yes. Upload a GPX track with time and elevation. The tool parses distance, elevation gain, and approximate duration automatically. You can still edit any field before calculating.
5) Does downhill always reduce energy cost?
Gentle downhills can reduce cost, but steep descents increase eccentric braking demands and may raise energy expenditure. Poles and technique can change the effect substantially.
6) How should I use hydration and carb targets?
They are guideline ranges. Start mid-range, then adjust by sweat rate, gut tolerance, weather, and duration. Include electrolytes in heat or long events. Practice fueling during training hikes.
7) Can I switch units and export results?
Yes. Toggle metric or imperial in the inputs. Export summary data as CSV or PDF using the buttons in the results panel. Files include inputs and outputs for sharing or records.