Marathon du Mont Blanc 2025 | Course | Altimetry
Marathon du Mont Blanc 2025: route, altitude, uphill/downhill statistics, gpx file
Note: "Marathon du Mont Blanc 2025" is NOT organized by goandrace.com
Marathon du Mont Blanc 2025 course map. Length: 42 km.
42 km (26.1 mi) course map of the event "Marathon du Mont Blanc 2025" in Chamonix (Friday, June 27, 2025). Explore the route!
Do you want to fly over the path with a Google Earth 3D video? Click on the following link: Marathon du Mont Blanc 2025, fly over the path (3D video).
GPS track - .gpx file download
Download the gps race path by clicking here. You can send the .gpx file to your Garmin watch or other compatible device and follow the path. For instructions on how to upload the GPX file onto your Garmin watch click here.
.gpx file download
NB: it is possible that the length calculated from the gpx file is greater than that of the race, with an error typically of 1-2%.
Click the following link to visit the Marathon du Mont Blanc 2025 event page.
Marathon du Mont Blanc 2025: route altimetric information
Marathon du Mont Blanc 2025: GNR-GAP index (v 1.0, experimental, see more)
Marathon du Mont Blanc 2025: interactive route
You can set the km (or mile) markers and you can select different types of layers (Satellite or Openstreetmap).
Marathon du Mont Blanc 2025: percentage distribution of slope
Marathon du Mont Blanc 2025: km by km elevation analysis
| Lap | Start Elev. | End Elev. | Elev. Diff. | Avg Slope | Min Elev. | Max Elev. | Total Ascent | Total Descent |
|---|---|---|---|---|---|---|---|---|
| KM 0-1 | 1042 | 1041 | -1 | -0.1% | 1040 | 1045 | 3 | 4 |
| KM 1-2 | 1041 | 1057 | +16 | +1.6% | 1041 | 1057 | 16 | 0 |
| KM 2-3 | 1057 | 1077 | +20 | +2.0% | 1058 | 1077 | 20 | 0 |
| KM 3-4 | 1077 | 1114 | +37 | +3.7% | 1078 | 1114 | 37 | 0 |
| KM 4-5 | 1114 | 1197 | +83 | +8.3% | 1116 | 1196 | 83 | 0 |
| KM 5-6 | 1197 | 1230 | +33 | +3.3% | 1198 | 1240 | 42 | 9 |
| KM 6-7 | 1230 | 1237 | +7 | +0.7% | 1207 | 1235 | 29 | 22 |
| KM 7-8 | 1237 | 1282 | +46 | +4.6% | 1238 | 1297 | 60 | 14 |
| KM 8-9 | 1282 | 1274 | -8 | -0.8% | 1265 | 1281 | 11 | 20 |
| KM 9-10 | 1274 | 1271 | -3 | -0.3% | 1259 | 1275 | 15 | 19 |
| KM 10-11 | 1271 | 1405 | +134 | +13.4% | 1270 | 1404 | 134 | 0 |
| KM 11-12 | 1405 | 1481 | +76 | +7.6% | 1408 | 1478 | 76 | 0 |
| KM 12-13 | 1481 | 1483 | +2 | +0.2% | 1481 | 1513 | 33 | 31 |
| KM 13-14 | 1483 | 1533 | +51 | +5.1% | 1477 | 1533 | 57 | 6 |
| KM 14-15 | 1533 | 1720 | +187 | +18.7% | 1536 | 1717 | 187 | 0 |
| KM 15-16 | 1720 | 1945 | +225 | +22.5% | 1720 | 1940 | 225 | 0 |
| KM 16-17 | 1945 | 2094 | +149 | +14.9% | 1945 | 2093 | 149 | 0 |
| KM 17-18 | 2094 | 2128 | +34 | +3.4% | 2095 | 2191 | 92 | 58 |
| KM 18-19 | 2128 | 1985 | -142 | -14.2% | 1986 | 2127 | 0 | 142 |
| KM 19-20 | 1985 | 1829 | -156 | -15.6% | 1833 | 1982 | 0 | 156 |
| KM 20-21 | 1829 | 1686 | -144 | -14.4% | 1687 | 1827 | 0 | 144 |
| KM 21-22 | 1686 | 1464 | -222 | -22.2% | 1467 | 1684 | 0 | 222 |
| KM 22-23 | 1464 | 1305 | -159 | -15.9% | 1305 | 1461 | 0 | 159 |
| KM 23-24 | 1305 | 1294 | -10 | -1.0% | 1269 | 1303 | 25 | 35 |
| KM 24-25 | 1294 | 1370 | +75 | +7.5% | 1296 | 1371 | 76 | 1 |
| KM 25-26 | 1370 | 1361 | -9 | -0.9% | 1328 | 1369 | 33 | 42 |
| KM 26-27 | 1361 | 1425 | +64 | +6.4% | 1361 | 1425 | 64 | 0 |
| KM 27-28 | 1425 | 1449 | +24 | +2.4% | 1427 | 1463 | 38 | 14 |
| KM 28-29 | 1449 | 1498 | +49 | +4.9% | 1424 | 1496 | 73 | 24 |
| KM 29-30 | 1498 | 1707 | +210 | +21.0% | 1498 | 1706 | 210 | 0 |
| KM 30-31 | 1707 | 1517 | -190 | -19.0% | 1519 | 1711 | 0 | 190 |
| KM 31-32 | 1517 | 1520 | +3 | +0.3% | 1465 | 1520 | 53 | 50 |
| KM 32-33 | 1520 | 1582 | +62 | +6.2% | 1520 | 1582 | 62 | 0 |
| KM 33-34 | 1582 | 1770 | +189 | +18.9% | 1582 | 1767 | 189 | 0 |
| KM 34-35 | 1770 | 1878 | +108 | +10.8% | 1773 | 1892 | 118 | 10 |
| KM 35-36 | 1878 | 1879 | +1 | +0.1% | 1864 | 1879 | 15 | 15 |
| KM 36-37 | 1879 | 1851 | -28 | -2.8% | 1851 | 1879 | 0 | 28 |
| KM 37-38 | 1851 | 1671 | -180 | -18.0% | 1673 | 1849 | 0 | 180 |
| KM 38-39 | 1671 | 1482 | -189 | -18.9% | 1484 | 1669 | 0 | 189 |
| KM 39-40 | 1482 | 1291 | -191 | -19.1% | 1296 | 1479 | 0 | 191 |
| KM 40-41 | 1291 | 1224 | -67 | -6.7% | 1206 | 1290 | 17 | 84 |
| KM 41-42 | 1224 | 1056 | -169 | -16.9% | 1056 | 1225 | 0 | 169 |
| KM 42-43 | 1056 | 1039 | -17 | -1.7% | 1039 | 1059 | 4 | 20 |
| KM 43-43.14 | 1039 | 1040 | +1 | +0.1% | 1039 | 1040 | 4 | 0 |
GNR-GAP index - Go&Race Algorithm Estimate
Based on the elevation profile analysis, running on this course is estimated to result in a pace that is 47.5% slower.
For example, a runner who maintains a pace of 5'00"/km (8'03"/mi) on a flat 43.1 km course, corresponding to a finish time of 3h35'43", is estimated to complete this course in 5h18'10". The recalculated average pace (GAP) improves to 7'22"/km (11'52"/mi), making it 2'22"/km (3'49"/mi) slower.
The following graph illustrates the Pace Adjustment (PA) factor applied to the pace along the course. The horizontal red line represents a PA of 1, meaning no pace adjustment. Above the line, the pace is slower; below the line, it is faster. The table below also provides estimates for other pace ranges.
Predict your race or analyze your performance!
This following table shows simulations for paces between 3 and 8 min/km.
RACE PREDICTION
To estimate a possible race time, use the "Pace" or "Time without slopes" column, which are valid for a flat course.
For example, if you think you can cover this distance on a flat course at a pace of 4'40"/km (or 7'31"/mi), i.e. in a time of 3h21'20", the estimate is to complete this course in 4h56'57", corresponding to a pace of 6'53"/km (or 11'05"/mi).
PERFORMANCE ANALYSIS
If you have run this race, use the table to estimate the equivalent time on a flat course. Check the "GAP" column and find the value closest to your pace, or compare the "Time with slopes" column with your time: on the same row you will find the pace and the equivalent time on a flat course in the "Pace" and "Time without slopes" columns.
For example, a time of 4h46'21" (pace of 6'38"/km or 10'41"/mi) corresponds to a time of 3h14'09" on a flat course (pace of 4'30"/km or 7'15"/mi).
| Pace (min/km) | Pace (min/mile) | Time without slopes (hh:mm:ss) | Time with slopes (hh:mm:ss) | GAP (min/km) | Δ Pace (min/km) | GAP (min/mile) | Δ Pace (min/mile) |
|---|---|---|---|---|---|---|---|
| 3'00" | 4'50" | 2h09'26" | 3h10'54" | 4'25" | 1'25" | 7'07" | 2'18" |
| 3'05" | 4'58" | 2h13'01" | 3h16'12" | 4'33" | 1'28" | 7'19" | 2'21" |
| 3'10" | 5'06" | 2h16'37" | 3h21'30" | 4'40" | 1'30" | 7'31" | 2'25" |
| 3'15" | 5'14" | 2h20'13" | 3h26'49" | 4'48" | 1'33" | 7'43" | 2'29" |
| 3'20" | 5'22" | 2h23'49" | 3h32'07" | 4'55" | 1'35" | 7'55" | 2'33" |
| 3'25" | 5'30" | 2h27'24" | 3h37'25" | 5'02" | 1'37" | 8'07" | 2'37" |
| 3'30" | 5'38" | 2h31'00" | 3h42'43" | 5'10" | 1'40" | 8'18" | 2'41" |
| 3'35" | 5'46" | 2h34'36" | 3h48'01" | 5'17" | 1'42" | 8'30" | 2'44" |
| 3'40" | 5'54" | 2h38'12" | 3h53'19" | 5'24" | 1'44" | 8'42" | 2'48" |
| 3'45" | 6'02" | 2h41'47" | 3h58'38" | 5'32" | 1'47" | 8'54" | 2'52" |
| 3'50" | 6'10" | 2h45'23" | 4h03'56" | 5'39" | 1'49" | 9'06" | 2'56" |
| 3'55" | 6'18" | 2h48'59" | 4h09'14" | 5'47" | 1'52" | 9'18" | 3'00" |
| 4'00" | 6'26" | 2h52'34" | 4h14'32" | 5'54" | 1'54" | 9'30" | 3'03" |
| 4'05" | 6'34" | 2h56'10" | 4h19'50" | 6'01" | 1'56" | 9'42" | 3'07" |
| 4'10" | 6'42" | 2h59'46" | 4h25'09" | 6'09" | 1'59" | 9'53" | 3'11" |
| 4'15" | 6'50" | 3h03'22" | 4h30'27" | 6'16" | 2'01" | 10'05" | 3'15" |
| 4'20" | 6'58" | 3h06'57" | 4h35'45" | 6'23" | 2'03" | 10'17" | 3'19" |
| 4'25" | 7'06" | 3h10'33" | 4h41'03" | 6'31" | 2'06" | 10'29" | 3'23" |
| 4'30" | 7'15" | 3h14'09" | 4h46'21" | 6'38" | 2'08" | 10'41" | 3'26" |
| 4'35" | 7'23" | 3h17'45" | 4h51'39" | 6'46" | 2'11" | 10'53" | 3'30" |
| 4'40" | 7'31" | 3h21'20" | 4h56'58" | 6'53" | 2'13" | 11'05" | 3'34" |
| 4'45" | 7'39" | 3h24'56" | 5h02'16" | 7'00" | 2'15" | 11'16" | 3'38" |
| 4'50" | 7'47" | 3h28'32" | 5h07'34" | 7'08" | 2'18" | 11'28" | 3'42" |
| 4'55" | 7'55" | 3h32'07" | 5h12'52" | 7'15" | 2'20" | 11'40" | 3'45" |
| 5'00" | 8'03" | 3h35'43" | 5h18'10" | 7'22" | 2'22" | 11'52" | 3'49" |
| 5'05" | 8'11" | 3h39'19" | 5h23'29" | 7'30" | 2'25" | 12'04" | 3'53" |
| 5'10" | 8'19" | 3h42'55" | 5h28'47" | 7'37" | 2'27" | 12'16" | 3'57" |
| 5'15" | 8'27" | 3h46'30" | 5h34'05" | 7'45" | 2'30" | 12'28" | 4'01" |
| 5'20" | 8'35" | 3h50'06" | 5h39'23" | 7'52" | 2'32" | 12'40" | 4'05" |
| 5'25" | 8'43" | 3h53'42" | 5h44'41" | 7'59" | 2'34" | 12'51" | 4'08" |
| 5'30" | 8'51" | 3h57'18" | 5h49'59" | 8'07" | 2'37" | 13'03" | 4'12" |
| 5'35" | 8'59" | 4h00'53" | 5h55'18" | 8'14" | 2'39" | 13'15" | 4'16" |
| 5'40" | 9'07" | 4h04'29" | 6h00'36" | 8'21" | 2'41" | 13'27" | 4'20" |
| 5'45" | 9'15" | 4h08'05" | 6h05'54" | 8'29" | 2'44" | 13'39" | 4'24" |
| 5'50" | 9'23" | 4h11'40" | 6h11'12" | 8'36" | 2'46" | 13'51" | 4'28" |
| 5'55" | 9'31" | 4h15'16" | 6h16'30" | 8'44" | 2'49" | 14'03" | 4'31" |
| 6'00" | 9'39" | 4h18'52" | 6h21'48" | 8'51" | 2'51" | 14'15" | 4'35" |
| 6'05" | 9'47" | 4h22'28" | 6h27'07" | 8'58" | 2'53" | 14'26" | 4'39" |
| 6'10" | 9'55" | 4h26'03" | 6h32'25" | 9'06" | 2'56" | 14'38" | 4'43" |
| 6'15" | 10'04" | 4h29'39" | 6h37'43" | 9'13" | 2'58" | 14'50" | 4'47" |
| 6'20" | 10'12" | 4h33'15" | 6h43'01" | 9'20" | 3'00" | 15'02" | 4'50" |
| 6'25" | 10'20" | 4h36'51" | 6h48'19" | 9'28" | 3'03" | 15'14" | 4'54" |
| 6'30" | 10'28" | 4h40'26" | 6h53'38" | 9'35" | 3'05" | 15'26" | 4'58" |
| 6'35" | 10'36" | 4h44'02" | 6h58'56" | 9'43" | 3'08" | 15'38" | 5'02" |
| 6'40" | 10'44" | 4h47'38" | 7h04'14" | 9'50" | 3'10" | 15'49" | 5'06" |
| 6'45" | 10'52" | 4h51'13" | 7h09'32" | 9'57" | 3'12" | 16'01" | 5'10" |
| 6'50" | 11'00" | 4h54'49" | 7h14'50" | 10'05" | 3'15" | 16'13" | 5'13" |
| 6'55" | 11'08" | 4h58'25" | 7h20'08" | 10'12" | 3'17" | 16'25" | 5'17" |
| 7'00" | 11'16" | 5h02'01" | 7h25'27" | 10'19" | 3'19" | 16'37" | 5'21" |
| 7'05" | 11'24" | 5h05'36" | 7h30'45" | 10'27" | 3'22" | 16'49" | 5'25" |
| 7'10" | 11'32" | 5h09'12" | 7h36'03" | 10'34" | 3'24" | 17'01" | 5'29" |
| 7'15" | 11'40" | 5h12'48" | 7h41'21" | 10'42" | 3'27" | 17'13" | 5'32" |
| 7'20" | 11'48" | 5h16'24" | 7h46'39" | 10'49" | 3'29" | 17'24" | 5'36" |
| 7'25" | 11'56" | 5h19'59" | 7h51'58" | 10'56" | 3'31" | 17'36" | 5'40" |
| 7'30" | 12'04" | 5h23'35" | 7h57'16" | 11'04" | 3'34" | 17'48" | 5'44" |
| 7'35" | 12'12" | 5h27'11" | 8h02'34" | 11'11" | 3'36" | 18'00" | 5'48" |
| 7'40" | 12'20" | 5h30'46" | 8h07'52" | 11'18" | 3'38" | 18'12" | 5'52" |
| 7'45" | 12'28" | 5h34'22" | 8h13'10" | 11'26" | 3'41" | 18'24" | 5'55" |
| 7'50" | 12'36" | 5h37'58" | 8h18'28" | 11'33" | 3'43" | 18'36" | 5'59" |
| 7'55" | 12'44" | 5h41'34" | 8h23'47" | 11'41" | 3'46" | 18'47" | 6'03" |
| 8'00" | 12'52" | 5h45'09" | 8h29'05" | 11'48" | 3'48" | 18'59" | 6'07" |
Notes on the calculation of the length, altimetry and slope
Note 1: the length of the route is calculated using the geographic coordinates. This value may differ slightly from the official length declared by the organizers.
Note 2: the altimetry may not correspond exactly to the real values. For routes obtained via Google API, it is possible that the altitude is that of the terrain, without considering tunnels or viaducts. If from GPS tracking, the error is arbitrary.
Note 3: the percentage slope is calculated on sections of at least 50 meters and smoothed. Roads with gradients between -3%% and +3%% are considered flat, between +3%% and +7%% are uphill, and greater than +7%% are considered steep.
