Mont Blanc measured at 4,807.47 metres, 1.88 metres higher than in 2023

A new reading after three years

Surveyors from the Haute-Savoie chamber of geometers measured Mont Blanc in September 2026 and put its summit at 4,807.47 metres. The figure is 1.88 metres above the 2023 measurement, so France's tallest mountain has gained close to two metres in three years. The results were presented on Wednesday, 14 October, at a press conference in Saint-Gervais, the French commune where the peak lies. The most recent fieldwork is dated 17 September, according to the reports.

1. 2001Haute-Savoie surveyors begin regular measurement campaigns
2. 2021Summit recorded at 4,807.81 metres
3. 2023Summit recorded at 4,805.59 metres
4. Sep 17, 2026Latest fieldwork gives 4,807.47 metres

What the number measures

The summit is a rock peak of roughly 4,792 metres, and the reported height includes a layer of snow and ice that sits on top of it. That layer changes from year to year, depending on wind, snowfall, sunshine and the weather of the months before each survey. Surveyors have been taking readings since 2001 and publish them every two to three years. Jean des Garets, president of the Haute-Savoie chamber of surveyors, told the press conference that the peak is always on the move.

The summit is constantly shifting.

He stressed that a single reading means little on its own. The value lies in a long run of data that can be analysed over time, which is why the surveyors keep repeating the work.

Each individual measurement is not significant in itself.

Earlier readings and rounding

Earlier surveys between 2000 and 2010 produced figures around 4,810 metres. The summit was recorded at 4,807.81 metres in 2021 and then at 4,805.59 metres in 2023, so the peak has moved both up and down within the survey record. The campaigns began in 2001, when the summit was measured at 4,810.40 metres.

2021

4807.81 m

2023

4805.59 m

2026-09

4807.47 m

Popular culture and pens sold under the same name still round the altitude to 4,810 metres. Des Garets defended that practice, saying the readings vary by several metres from one year to the next, so rounding to the nearest ten is 'quite reasonable'. The latest figure is close to the value obtained by the Vallot cousins at the end of the nineteenth century, the surveyors noted.

What glaciologists see

Luc Moreau, a glaciologist who attended the press conference, said the summit has so far changed little under the influence of warming. He welcomed the series of measurements, which he said would allow scientists to keep watching how the snow-covered summit evolves in the future.

It is still cold; it has not yet been changed much by the climate.

The surveyors also warned that the snow cap responds to many factors at once, including accumulation, precipitation, wind, the redistribution of snow, temperatures and sunshine, so no single reading should be taken as a trend. The Haute-Savoie team plans to keep publishing its results every two to three years.