Trek Time Calculator — Realistic Hours, Not Optimistic Ones
Guidebook times are written for acclimatized porters, not jet-lagged tourists carrying a pack at altitude. This calculator uses Naismith's rule (5km/h + 1 hour per 600m of climb) with an altitude penalty — because 5km/h at sea level becomes 3km/h at 4,500m.
Why the Adjustment Matters
- Naismith's rule (1865): 1 hour per 5km + 1 hour per 600m elevation gain — still the standard, but written for sea level
- Altitude penalty: above 3,000m, your pace drops 15–30% as oxygen falls; above 4,000m, 30–40% slower
- Add 30–60 min for breaks — photo stops, tea breaks, rest — nobody walks continuously
- Downhill isn't "free" — descents take about 60–70% of uphill time, not zero; knee pain slows them further
The Safety Buffer Rule
Whatever the calculator says, add a 30% buffer when planning arrival times — weather, photo stops, acclimatization wobbles, and trail conditions always cost more time than planned. If a stage arrives after dark, it was planned too tight.
The Pace That Finishes
The trek that succeeds is the one paced to be sustainable — not the pace that is impressive but the one that can be maintained for the day, then repeated for the week. The breathing that allows conversation, the rhythm that continues for hours, the slowness that is strategy not weakness. The calculator provides the number; the discipline is keeping it.
Pacing rules
- Talk-test pace — you can hold a conversation
- Nose breathing possible — not gasping for air
- Deliberately slow at altitude — the pace that feels easy
- Consistent rhythm — steady beats fast-and-rest cycles
- Energy reserve — never push to the point of emptiness
The Altitude Pace Adjustment
The pace that feels normal at sea level is too fast at 4,000m — the cardiovascular capacity is reduced, the oxygen is scarcer, and the exertion that was sustainable is not. The rule: whatever pace you think is right, go slower. The altitude trek is not the fitness test; it is the endurance test where the conservative pace wins.
The Trek Pace
Trek pace — the slow steady (the 4-6 km/hr that is typical), the rest that is taken, and the altitude gain that is gradual. For the trek, the pace that is sustainable.
The Day Length
Trek day length — the 4-7 hours that is typical (the not the marathon that exhausts), the morning that is the best, and the afternoon that is the slower.
The Calculator Cost
Pace calculator — the free (the planning tool that costs nothing). For the itinerary, the pacing that is computed.
The Wrong Pace Cost
Wrong-pace cost — the AMS, the missed day, the evacuation (the rushed that is expensive). For the itinerary, the slower plan that is the cheap insurance.
The Free Calculator
Pace calculator — the free (the itinerary-planned that is the tool). For the planner, the calculated that is the value.
The Mis-Paced Cost
Wrong-pace cost — the extra-day/evac (the ~$50-500+ that the rushed costs). For the planned, the correct that is the cheap.
What pace should I walk while trekking?
A pace you can sustain for hours — not the pace that feels fast but the one you can maintain while talking in sentences. If you are breathing too hard to converse, you are going too fast. The trekking pace is deliberately slow — the person who walks at a pace they could sustain all day outperforms the one who sprints and rests.
How do I pace myself at altitude?
Slower than sea level — the same pace that feels normal at home feels hard at altitude. The rule: start slower than feels necessary, maintain a pace where you can breathe through your nose or talk easily, and let the pace be boring. The trekker who saves energy early has it for the summit push.
What is a good speed for trekking?
3–4 km/h on flat terrain, 2–3 km/h uphill, 4–5 km/h downhill — but the pace is individual. The calculator adjusts for your fitness and the terrain. The important metric is not km/h but sustainability — the pace you can maintain for the day's duration.
Should I walk fast to acclimatize faster?
No — faster walking does not accelerate acclimatization; it increases fatigue and masks AMS symptoms by attributing them to exertion. Acclimatization requires time at altitude, not speed. The pace should be slow enough that altitude stress is the limiting factor, not cardiovascular exhaustion.
How do I pace on summit days?
Slow and steady — the pre-dawn start in the cold means pacing matters more than speed. Start slower than feels possible, maintain rhythm through the steep sections, and budget energy for the descent (which is harder on the legs than the ascent). The summit push is a pacing exercise, not a race.
