December 9, 2018
By BCA Ambassador Sarah Carpenter
How often do you head out on a ski tour with a really good idea of how long it’s going to take you? For me, I know how long my go-to backcountry tours take, but when headed somewhere new, it can be daunting to not only figure out a route but also figure out how long that route will take. So I’ve put together a method for how to calculate ski tour time based on distance and elevation gain.
There are a variety of travel time calculators out there. Some of the online options are great. Some need a little help. I have built a base level of understanding on how to calculate tour times by measuring the distance traveled and the elevation gained.
You can go deep and get really into the weeds with this calculation, based on the Munter Method, or you can guestimate and hone in on tour times as you do more and more tours. When I’m working as a ski guide, gaining 1000 feet of elevation takes an hour. And when I’m guiding, traveling a 1 1/2 to 2 miles takes an hour. So…I can estimate our travel day based on measuring the distance of my tour as we go uphill (one hour per one mile) and the elevation gained (one hour per one thousand feet).
As for downhill travel, I base it on the ski skills of my partners and the snow conditions. On a good guiding day, in blissful powder, a 3000’ vertical run can take me 10-20 minutes. This includes giving instructions, regrouping in safe zones, and moving through terrain efficiently. On a day with poor snow or a skier who is challenged by the conditions, it can take an hour…or more. So, with a little bit of simple math and an idea of ski conditions, I can show up at the parking lot with a good idea of how long a tour day is going to take me.
Now, if the rough estimate isn’t enough, then the Munter Method is a great tool. Pull out a topographic map, or find an online map program, such as Gaia or MountainHub. Draw in your route – both the ascent and the descent. And then break this route into legs. Each leg of the route is the travel between breaks. I like to split my ski route into ascent legs and descent legs, as they take different amounts of time and energy.
Once you have defined your legs, it’s time for a spreadsheet or a little math on the back of a napkin. Munter’s calculation is TIME = (DISTANCE (km) + ELEVATION (m)/100))/rate. RATE is your rate of travel. In general, going uphill on skis or in a bootpack, your rate of travel is 4, as in 4 units per hour. When you’re going downhill on skis, on average, the rate of travel is 10, as in 10 units per hour.
When you’re calculating your ski route times, start by figuring out the distance of each leg in kilometers. Figure out the elevation gain or loss of each leg in meters and divide this by 100. Add these two numbers up. And now refer to your rate of travel – are you going uphill or downhill? Divide your (Distance + Elevation) by your (Rate of Travel). And now you have an estimate of the time it will take to complete your tour.
EXAMPLE: HOW TO CALCULATE YOUR SKI TOUR TIME
The first leg of my tour is 2.5 miles and gains 3000 feet. If I convert that (thank you google), I get 4 km and 1000 m of elevation gain….which is then 4 units + 10 units = 14 units. If I’m going uphill, I estimate that this will take me 3 ½ hours. (14/4).
The second leg of my tour is turning around and skiing/riding out. So…2.5 miles and losing 3000 feet. Again 4 units + 10 units. This time, divide this by 10 for traveling downhill. I estimate the return trip will take me 1 hour and 25 minutes.
This means my total tour time will be about 5 hours.
And after doing the math, the best part about this calculation is testing it out. Are you traveling at the average pace? Above average? Are you cruising but taking long breaks? The beauty of this time and distance calculation is that you can adjust it based on testing. It varies depending on the group you’re traveling in.
I encourage you to spend some time planning your routes and estimating your travel time. Try the quick and dirty method of 1000 feet = 1 hour and 2 miles = 1 hour and see what you come up with. Then use the Munter Method to refine your calculation. Have them both written down, so you can field test them and adjust your estimates based on who you are traveling with, the snow conditions, or how long the breaks you’re taking are. Let me know how it goes!