The 11 Tour du Mont-Blanc variants, measured one by one (what they really cost)

On the Tour du Mont-Blanc, a variant often gets judged by the wrong measurement. The usual question is how many kilometers it adds, but on this route distance predicts almost nothing. If you've ever hiked a multi-day trip in the Rockies or on the West Coast Trail, you already know the feeling: the map distance and the day's actual effort rarely match up. Measure all eleven TMB tracks one by one, and three of them come out shorter than the route they replace: the Petit Col Ferret by 4 km, the col des Fours also by 4 km, and the Fenêtre d'Arpette by 3 km. The first two barely cost anything extra in climbing either. The third adds 425 more meters and stays the hardest day of the tour.

At Altimood, we guide groups on this route and record the tracks ourselves, season after season. This article lines up all eleven usable variants against the section they replace, with the real difference in distance, elevation gain and walking time. Each one comes with its own downloadable GPX track.

One thing worth clarifying before the numbers: "worth it" isn't a data point, it's an opinion. Ours depends on the morning weather, how the group is doing, and what we've already seen on the days before. The measurements themselves don't change, though, and that's what lets us talk about everything else on solid footing.

The 11 variants compared to the classic route

Each row compares the variant to the exact section it replaces, with identical start and end points on both sides. The differences are measured on our own tracks, smoothed the same way as the elevation profiles further down. Time is calculated for a steady hiker carrying a trekking pack, roughly 370 m of climbing per hour.

The ranking here runs by elevation cost, cheapest to priciest, not by distance. That's the number that actually matters on a multi-day trek: kilometers can be made up, but meters of climbing keep piling up from one day to the next.

So read both columns together, never separately. The Fenêtre d'Arpette makes the point best: 3.3 km shorter, yet still the hardest day of the circuit, because it climbs 425 meters more over a scree slope. The col des Fours, on the other hand, is the only variant that's negative on both counts, and the Petit Col Ferret isn't far behind, its extra thirty-five meters of climbing barely worth mentioning. Those two are the real bargains of the tour.

The table also settles a question that comes up often: where the tour's highest point actually is. On the main route, the TMB tops out at the Grand Col Ferret, 2,537 m. Bring the variants into it, and the highest ground actually walked on any one itinerary is the Mont-Fortin traverse, around 2,730 m, on the mountain's flank rather than its summit. Higher still, but as an out-and-back rather than part of the tour itself, the Tête Nord des Fours (2,756 m) is twenty minutes from the col des Fours: it's the highest point your boots will ever actually touch on the whole route. And two passes share the exact altitude of 2,665 m, the col des Fours and the Fenêtre d'Arpette, one in France and the other in Switzerland. The "high point" column gives the official altitude of the spot itself, which our tracks come within a few meters of, except where the trail deliberately dips below the summit.

What a variant really costs

The classic TMB route runs about 170 km for around 10,000 m of elevation gain. String together the six high-altitude variants, col du Tricot, col des Fours, Mont-Fortin, Mont de la Saxe, Fenêtre d'Arpette and Lac Blanc, and the distance barely moves, while elevation gain climbs by about 1,800 m.

That's really the whole story. On this route, you don't pay for a variant in kilometers, you pay for it in climbing. The high-altitude trails cut straight over the passes while the main route swings around lower down, so they end up covering a little less distance but a lot more height. Across the whole tour, the distance gap adds up to a few hundred meters at most, which is basically nothing: it's below what any track measurement can even pick up on.

The 1,800 m of climbing, though, you'll feel that one. It works out to nearly 20% more effort across the whole route, and it stretches the days out even when the map shows the same length. A tour with every variant included is noticeably harder than one without, full stop. What the measurement gives you is simply knowing where to look: the elevation column, never the kilometer one.

So the call really comes down to your legs, your schedule and the next day. To see what those 1,800 meters do to your own itinerary, our TMB duration calculator factors in all eleven variants from this article and recalculates the nights accordingly, taking into account which lodgings each one skips.

The variants that cost almost nothing

Four variants can be taken without reorganizing the day at all. Between them they add less than 100 meters of climbing, and one of them actually removes some.

The col des Fours, 2,665 m, stage 2

This is the only variant on the whole tour that's both shorter and less climbing than the route it replaces: 3.8 km and 40 meters of elevation gain less. It comes down to geography. From the refuge de la Croix du Bonhomme, the classic path drops 900 meters to Les Chapieux, down in the valley floor, before climbing back up 320 meters to Les Mottets. The variant, instead, keeps climbing another 190 meters to the col des Fours, then drops straight into the vallée des Glaciers and rejoins the TMB further down.

So you walk less to end up higher. The view from the pass, at 2,665 m, opens onto the Écrins to the south and the Mont-Blanc massif to the north. With time and clear skies, an easy shoulder extends due north from the pass to the Tête Nord des Fours (2,756 m) in about twenty minutes, the best viewpoint in the area.

What the variant really costs is the night at Les Chapieux. The hamlet is a resupply point and one of the few places in this area where you can sleep, and the col des Fours bypasses it entirely. It's a scheduling call as much as a route choice, one to make when booking, not the morning of.

The other condition is the weather. At 2,665 m on an exposed shoulder, a storm is something you just have to ride out. The snow patch on the descent to the Ville des Glaciers often holds until early July, and that steep descent is what eats up, on the ground, the theoretical 55-minute head start. Expect roughly the same time as via Les Chapieux, just with different scenery.

• Distance :↔ 5.9 km
• Dénivelé positif :↗ 228 m
• Dénivelé négatif :↘ 873 m

The full breakdown of the day and the comparison with the classic descent are in stage 2, Les Contamines to Les Chapieux.

The Petit Col Ferret, 2,490 m, stage 6

This is the best bargain on the tour, and by far the least known. Between the Rifugio Elena and La Fouly, the Petit Col Ferret (2,490 m) comes in 3.7 km shorter than the classic passage via the Grand Col Ferret, for just thirty-five extra meters of climbing. Thirty-five meters is measurement noise. So that's close to four kilometers and three-quarters of an hour handed to you for free.

The explanation is in the descent, not the climb. The classic pass drops onto the alpage de La Peule and follows the whole upper Val Ferret on the Swiss side before reaching La Fouly. The Petit Col Ferret, forty meters lower and one kilometer further west, drops more directly into the valley. On the track, it passes two and a half kilometers from La Peule without ever seeing it.

That's also what makes it less of a slam dunk than it looks. The Swiss side of the Petit Col Ferret is steeper and far less traveled, the trail fainter underfoot, and the alpage de La Peule you're skipping is one of the best stops on the Swiss side, cheeses and terrace included. You save time by giving up a break that plenty of hikers rank among their favorite memories of the trip.

Our take: it's worth it on a day when time is tight, or when the weather is closing in and you need to be down early. On a normal day, La Peule is worth walking the four kilometers for.

• Distance :↔ 7.9 km
• Dénivelé positif :↗ 488 m
• Dénivelé négatif :↘ 926 m

The classic route via the Grand Col Ferret (2,537 m), the high point of the main route, is described in stage 6, refuge Bonatti to La Fouly.

The Mont-Fortin, 2,758 m, stages 3 and 4

Ninety extra meters of climbing and four hundred extra meters of distance, for an almost continuous ridge walk above the Val Veny. On paper, it's the best bargain of the bunch.

Out on the ground, it's the most committing variant on the list, and the table doesn't show that. It starts right after the col de la Seigne, follows the col des Chavannes (2,598 m), the flank of the Mont-Fortin, then the col de Youla (2,661 m), and drops to the Col Chécrouit. Almost the whole thing runs above 2,500 m, far from anything, with no bail-out option once you're committed. Our track tops out at 2,730 m.

It's more of a high-route traverse than a TMB variant. We'll only run this with groups already seasoned at altitude, in stable weather, with a comfortable time margin. The real cost isn't the 90 meters, it's the commitment.

This variant also bypasses the Rifugio Elisabetta, the natural lodging for this section, so it changes how stages 3 and 4 get split.

• Distance :↔ 18.5 km
• Dénivelé positif :↗ 1151 m
• Dénivelé négatif :↘ 1124 m

The classic passage below the Mont-Favre ridge is described in stage 4, Rifugio Elisabetta to Courmayeur.

The ladder bypass, stage 10

This isn't a scenery variant, it's a fix. The eleven metal ladders at Trè-le-Champ put off a good number of hikers, and a marked trail avoids them via the col des Montets. It adds 2.1 km and only 85 meters of elevation gain.

Its real value lies elsewhere: measured on the track, this bypass rejoins the TMB at the Tête-aux-Vents (2,132 m), which is upstream of the Lac Blanc turnoff. So skipping the ladders doesn't cost you the lake, contrary to what the map suggests at first glance.

• Distance :↔ 8.2 km
• Dénivelé positif :↗ 771 m
• Dénivelé négatif :↘ 329 m

The circuit's other exposed sections and their bypasses are detailed in our article on the Tour du Mont-Blanc for hikers afraid of heights.

The variants that cost an hour or two

Three variants fit within a morning's head start. They get decided on the day, with a look at the sky.

The Aiguillettes des Houches, 2,285 m, stage 11

On the last day, instead of dropping straight from Bellachat to Les Houches, you extend along the Aiguillettes des Houches ridge before heading down. The variant adds 3.4 km and 180 meters of climbing for about 1h15.

It's the least taken of the eleven, and that tracks: on day eleven you've got a train to catch, tired legs, and a tour already wrapped up in your head. It mostly pays off if you're finishing early and want to stretch out the last descent instead of just enduring it. This side is also noticeably quieter than the direct trail.

• Distance :↔ 9.4 km
• Dénivelé positif :↗ 178 m
• Dénivelé négatif :↘ 1330 m

The classic route via the Brévent is described in stage 11, La Flégère to Les Houches.

The Lac Blanc, 2,352 m, stage 10

The most photographed detour in the Alps costs 1.7 km and 285 meters of climbing from the Tête-aux-Vents, roughly 1h30 round trip. The lake's milky color comes from rock particles ground down by glacial abrasion, and the reflection of the Drus in the first pool is the shot everyone's seen.

It's the tour's most weather-dependent variant, by a wide margin. Under clear skies, it's easily worth the hour and a half. Under a low ceiling, all that's left is a gray lake and a climb for nothing, so the energy is better saved. It's also the only one on the list you can decide at the very last second, since the turnoff is at the cairn on the Tête-aux-Vents, with the sky right there in front of you.

Since stage 10 is the shortest on the circuit, this detour almost never causes a scheduling headache.

• Distance :↔ 7.8 km
• Dénivelé positif :↗ 973 m
• Dénivelé négatif :↘ 533 m

The lake also makes a great day hike outside the TMB: see our article on Lac Blanc from Chamonix.

The Prarion, 1,967 m, stage 1

Starting from Les Houches, instead of climbing to the col de Voza on the GR trail, you follow the GRP Tour du Pays du Mont-Blanc up to the summit of the Prarion (1,967 m), then drop back down to the col de Voza. The variant adds 4.6 km and 300 meters of climbing, the longest add-on on the list, though not the hardest.

Its appeal is as much social as scenic. Day one of the TMB is when you'll cross paths with the most people, since everyone leaves Les Houches around the same time. The Prarion side sits away from that crowd and away from the lifts, climbing through shaded forest before opening onto a 360-degree view that takes in the Mont-Blanc massif, the Chamonix valley and the Aravis.

Good option to know about if you're setting off in peak season and the first day's crowds worry you.

• Distance :↔ 12.6 km
• Dénivelé positif :↗ 1007 m
• Dénivelé négatif :↘ 660 m

The variants that cost half a day

The last four come at a real price. They call for the day to be planned ahead, not decided over breakfast.

The Fenêtre d'Arpette, 2,665 m, stage 8

This is the big dilemma on the Swiss side. Between Champex-Lac and Trient, the Fenêtre d'Arpette comes in 3.3 km shorter than the Bovine route, and that's the number that surprises everyone. It doesn't make the day any easier for it: it climbs 425 meters more, concentrated on a scree slope, and stays the most demanding day on the circuit. Walking less distance while climbing more, on terrain like this, never adds up to an easier day.

The time calculation shows only an hour's difference, but this is where the model hits its limit. The final stretch below the gap is the most technical passage on the tour: loose rock, a faint trail, cairns as the only waymarking. A group moving carefully will lose a lot more than an hour there, and in fog, route-finding becomes the real issue. Early in the season, snow patches cover the passage into July.

Our rule is simple. Clear skies, snow melted out, eight days of walking already in the legs, and a group comfortable on scree: it's the best day the Swiss side has to offer, with the glacier du Trient right in front of you on the way down. Any doubt on one of those four points: take Bovine, no regrets, and the alpage more than makes up for it.

• Distance :↔ 12.9 km
• Dénivelé positif :↗ 1185 m
• Dénivelé négatif :↘ 1341 m

The full comparison of both routes is in stage 8, Champex-Lac to Trient.

The Mont de la Saxe, 2,584 m, stage 5

Above the Rifugio Bertone, a trail leaves the classic balcony route and climbs onto the ridge overlooking the Italian Val Ferret. On our track, measured from the Bertone to the Bonatti, it adds 2.6 km and 465 meters of elevation gain and tops out at 2,554 m. Push on to the high point at the Tête de la Tronche (2,584 m) and you'll add roughly another hundred meters.

If we had to keep just one of the eleven, this would be it. The ridge unrolls a continuous panorama over the Grandes Jorasses, the Dent du Géant and the Aiguille Noire de Peuterey, less than four kilometers away, with no blind spots and hardly anyone to share it with, since most hikers stick to the lower trail. The classic route via Armina is pretty and sheltered, but it's not in the same league.

The price is a fair one, and it's steep, literally. Four hundred sixty-five meters of unbroken climbing first thing in the morning, on a ridge with no water and no shade, on day five of the tour. In strong wind or under an overcast sky, it loses its appeal fast and keeps every bit of its cost.

• Distance :↔ 9.8 km
• Dénivelé positif :↗ 676 m
• Dénivelé négatif :↘ 630 m

The full breakdown of the day is in stage 5, Courmayeur to refuge Bonatti.

The refuge de Tré-la-Tête, 1,970 m, stage 2

This is the most lopsided variant in the table, and it's worth reading carefully. It replaces 3.6 km of valley floor between Les Contamines and the refuge de Nant-Borrant, a flat stretch that gains 276 meters without ever losing any. The variant, instead, climbs to the refuge de Tré-la-Tête (1,970 m) before dropping back down to Nant-Borrant: 555 more meters of climbing, 4.1 km more, and close to three extra hours of walking.

The ratio looks brutal because the section it's replacing happens to be the easiest on the circuit. It's not that the variant is hard in absolute terms, it's that the alternative is an almost flat forest track, one of the rare stretches on the TMB where you walk without much effort.

What you gain is a balcony above the val Montjoie, facing the Dômes de Miage and the glacier de Tré-la-Tête, while the valley floor stays under forest cover the whole way. The refuge itself is a great stop, old and well kept.

What you lose is the day's only real stretch of recovery. Stage 2 ends at the col de la Croix du Bonhomme, at 2,443 m, after a long climb. Adding 555 meters and three hours ahead of that climb turns a reasonable stage into a genuinely huge day. In practice, this variant only really works if you split stage 2 in two and sleep at Nant-Borrant or at la Balme.

• Distance :↔ 7.7 km
• Dénivelé positif :↗ 834 m
• Dénivelé négatif :↘ 537 m

The classic route through the val Montjoie is described in stage 2, Les Contamines to Les Chapieux.

The col du Tricot, 2,120 m, stage 1

This is the priciest variant on the tour: 575 meters more elevation gain than via the col de Voza, for an extra 2.1 km and roughly two more hours of walking. It's also the one most often taken.

From the col de Voza, the trail passes below the hôtel de Bellevue, drops toward the Himalayan-style footbridge suspended above the torrent de Bionnassay, then climbs steeply through gravel up to the col du Tricot (2,120 m), facing the glacier de Bionnassay and the Dômes de Miage. It then drops back down to the refuge de Miage before rejoining Les Contamines.

The real problem with the Tricot isn't its difficulty, it's where it falls in the day. Those two hours land on day one, when the pack is at its heaviest and the body hasn't absorbed anything yet. On a tight itinerary, you keep paying for that all week.

That's exactly why scheduling matters more than leg strength here. A 10-day TMB itinerary splits the first day in two and sleeps at Bionnassay, which makes the Tricot comfortable from the very first morning. On a tight tour, the same variant becomes a gamble.

• Distance :↔ 19.3 km
• Dénivelé positif :↗ 1541 m
• Dénivelé négatif :↘ 1363 m

Both first-day routes are compared in stage 1, Les Houches to Les Contamines.

When each variant opens up

The variants don't open up on the same schedule as the tour itself. A mid-June TMB hikes perfectly well on the main route while half the high variants are still under snow, and it's the question we get asked least, even though it decides everything for an early departure.

The last three to clear are the col des Fours, the Fenêtre d'Arpette and the Mont-Fortin. Expect early July for the col des Fours, whose descent to the Ville des Glaciers faces north and holds snow well after the pass itself is dry. Expect the same window for the Fenêtre d'Arpette, where the scree below the gap stays under snow longer than the rest of the valley, and where a steep snow patch over boulders is a far more serious matter than one over an alpine meadow. The Mont-Fortin, which holds a long ridge above 2,500 m, has to be judged case by case depending on the winter.

The others can be taken as soon as the huts open. The col du Tricot, the Mont de la Saxe and the Lac Blanc can carry residual patches in June, but on terrain that's still passable. The Prarion, the ladder bypass and the Aiguillettes des Houches raise no seasonal question at all.

One thing no map shows: two of these variants are dry. The Mont de la Saxe ridge has no water source between the Rifugio Bertone and the Bonatti, and the high section above the Lac Blanc has none either until the Flégère. Two liters per person at the start isn't just caution, it's the bare minimum.

How we choose, in order

Out on the ground, the trade-off always follows the same order, and the view comes last.

First comes lodging, because it's booked six months ahead and can't be fixed later. Three variants change how the nights are split: the col des Fours skips Les Chapieux, the Mont-Fortin skips the Rifugio Elisabetta, and the Fenêtre d'Arpette means starting from Champex rather than an intermediate point. Those three get decided at booking time. Our roundup of Tour du Mont-Blanc mountain huts maps out the addresses involved.

Next comes the morning weather, and above all the expected arrival time at the high point. The col des Fours, the Mont-Fortin and the Fenêtre d'Arpette all run over exposed terrain above 2,600 m. A storm forecast for early afternoon rules out all three, no matter how strong the group is.

Then comes the state of your legs, factoring in the following day and not just the one at hand. A variant with 500 meters of climbing rarely costs you that evening: it costs you the next morning.

The view comes after that. It only settles things between whichever options are left, and there are almost always some left.

One last habit, the one that heads off the most bad days: plan the itinerary without the variants, then add them on the day when everything lines up. A short day can be stretched at will on this circuit. A day built around your best-case scenario can't be shortened once you're already committed.

The other departures from the route, and what they're worth

The TMB has other departures from the main route that we left out of the table, because they don't follow the same logic.

The Aiguillette des Posettes deserves a clarification, because it's often presented as a variant of stage 9 when it isn't one, the TMB already runs along the ridge: it drops to the col des Posettes around 2,010 m, climbs back above 2,150 m along the crest, then heads down to Trè-le-Champ. What does exist here as a genuine alternative is the low-level descent via Charamillon and Le Tour, which shortens the day by dropping below the lifts. It's also the descent most hikers end up drawn into anyway.

Valley connections are a different animal. The descent to Vallorcine instead of via Trè-le-Champ, the bottom of the Swiss Val Ferret by road, the exit via Le Tour and Montroc: these aren't mountain variants, they're fallback options. They save elevation gain on a day when the weather turns or an ankle starts acting up, and that's exactly what they're there for. Better to keep them in mind than to discover them in the rain.

The refuge Robert Blanc area (2,750 m), above the Mottets, is another matter entirely. The col d'Enclave, the sentier Thomas Roques and the col des Bouquetins form a high-route network that crosses the TMB without being part of it: cabled sections, long days, high-altitude terrain. The Mont-Fortin already sits on that borderline, and we kept it because it stays waymarked and technically straightforward apart from a demanding scree descent. Beyond that, those are separate hikes, and should be planned as such.

Mechanical shortcuts, lastly, aren't variants but they do change a trip significantly: the tramway du Mont-Blanc, the Brévent cable car, the Checrouit gondola above Courmayeur, the Swiss postal buses. Their effect on the number of days is covered in our article on how many days the TMB takes.

Frequently asked questions about TMB variants

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