With Adam Ondra’s epic ascent of Silence, the climbing world was elevated to an entirely new level of possibility.
But what the heck is 9c in the Yosemite/5.10 climbing rating scale? Or, in the Australian grading system?
Let’s find out!
Keep reading below for a conversion chart followed by an explanation of these ratings as well as alpine, water-ice, boulder, and commitment ratings.
Here is what we are going to look at (click the titles to skip ahead):
- A Little History
- Free Climbing Ratings: French, Yosemite/5.10, UK, Australian, UIAA
- Aid Ratings
- Bouldering Grades: Hueco/V, Font/Bleau
- Commitment Grades
- Alpine Grades
- Water-Ice Grades
- Putting It All Together
Here is a free conversion chart. Screenshot it, save it, share it, or download it so you’re never without easy access to this handy climbing rating conversion chart.
Rock Climbing Ratings
Since its inception, rock climbing has been a fringe sport.
Climbers lived at the edges of society pushing the boundaries of vertical human capabilities with little notice from the outside world.
It was not until recently—the last 15 years and more so the last 5 years—that climbing became a globally recognized phenomenon.
Heck, its even in the Olympics now!
As a result of climbing’s isolated developments across the globe, people came up with different ways to grade the climbs in their specific regions.
Today, we have a handful of rock climbing and alpine climbing rating scales that help the entire community understand what they’re getting into when roping up at the base of a climb.
History Of Climbing Ratings
The first known grading system for rock climbing was introduced in 1894 by Austrian mountaineer Fritz Benesch.
In his scale there were 7 levels of difficulty with 1 being the hardest and 7 the easiest.
This system was improved upon in 1923 by German climber Willo Welzenbach.
His scale consisted of grades numbered 1-6 with 5 being the hardest and 6 reserved for aid climbing.
This grading system was quickly adopted by French mountaineers and the UIAA and is still the base of the Yosemite Decimal System used in North America today.
Free Climbing Ratings
By ‘free-climbing’ we mean climbing up a rock face using hands and feet (or other body parts) without the use of aid gear to assist in your ascent outside of as protection in case of falls (aid climbing has its own rating system—shown below).
The most common free-climbing rating scales are the French, US or Yosemite Decimal System, and the UK scale.
Free climbing grades are generally understood to reflect the hardest move or section on a particular route. They do not indicate time commitment or duration.
This metric is graded by the NCCS (National Climbing Classification Scale). More on that below.
French Climbing Scale
Not to be confused with the Fontainebleau scale for bouldering, the French system is the most common free climbing rating scale outside of North America.
The French simplified the rating system by starting at 1 and working their way up in difficulty—1 being the easiest.
From level 4 on, French grades add letters a-c for incremental increases in difficulty.
Adding another increment, starting at level 6 French grades include an + with each letter.
For example, the French climbing scale—from easiest to harder— would look like this:
1, 2, 3, 4, 4a, 4b, 4c, 5a, 5b, 5c, 6a, 6a+, 6b, 6b+, 6c, 6c+, 7a, 7a+, 7b, 7b+, 7c, 7c+, 8a, 8a+…
Currently the hardest known free climb in the world is an 9c.
For reference, that is 5.15d in the YDS system, and a 39 in the Australian system.
Yosemite Decimal System
North Americans climbers use the Yosemite Decimal System (YDS).
Despite its namesake, the YDS was not developed in Yosemite but in Tahquitz (a granite climbing area in Southern California).
During the 1930s the Sierra Club adopted a variation of the Welzenbach scale to rate hikes and scrambles in the Sierra Nevadas.
A few decades later the Rock Climbing Section of the Sierra club working out of Tahquitz expanded on that grading system to come up with the YDS.
In this system classes 1-5 are defined like this:
- 1st Class: Walking on even terrain and/or established trails.
- 2nd Class: Walking/hiking at an incline, scrambling where the use of hands is required at times.
- 3rd Class: Steeper climbing with some exposure and consistent use of hands where short falls are possible.
- 4th Class: Steeper than previous classes where long falls are of high potential and ropes become useful.
- 5th Class: Technical climbing where hands and feet are in constant use, technical gear and ropes are used, and any fall may be fatal.
The ‘5’ in 5.10 for example, represents 5th class climbing.
So YDS uses 5th class as the base and builds from there by adding numbers after the decimal point.
5.1 would be an easy climb with rock shoes, protective gear, and a rope.
The Sierra Club took a handful of climbs at Tahquitz and based their ratings on the difficulty of these climbs.
At that time, the hardest climb was one they rated at 5.9.
Within a short time, hower, it became obvious that this upper limit was inadequate.
As climbing abilities and technology rapidly progressed the scale was correspondingly increased until today where we have climbs rated up to the high 5.15s.
YDS ratings all start with ‘5.’ Like the French system, the YDS uses letters above 5.9 to create increments between full number grades.
The only difference being that YDS uses a-d without ‘+’ increments instead of a-c.
As shown above, this gives the French system 6 increments per number grade, while allowing 4 increments per number grade in the YDS.
At times you might see YDS rated climbs graded with a ‘+’ or ‘-.’
In these situations the letters are left out and only the plus or minus is given.
As a general rule, this gives another variable to climbs easier than 5.10 or an in-between rating by the first ascentionist or author.
For example, a 5.11+ would be considered a ‘hard’ 5.11, whereas a 5.11- would be considered an ‘easy’ 5.11.
A standard YDS scale looks something like this:
5.8, 5.9, 5.10a, 5.10b, 5.10c, 5.10d, 5.11a, 5.11b, 5.11c, 5.11d, 5.12a…etc.
UK Grading System
Rock in the UK can be very different from other parts of the world.
For this reason, the UK has a bit more complex rating system for free climbs.
This is a two part system with two designations to account for two different factors involved in each route.
Today, the two part UK scale is only used for trad climbs. Sport climbs in the UK are rated with the French system shown above.
The first part of the rating is an subjective scale that attempts to quantify the overall difficulty of a route.
For example: Is it run out? How often are there good gear placements? What’s the rock quality like? etc.
This first half of the scale goes from Easy to Extremely Severe and looks like this:
- E: easy
- M: moderate
- D: difficult
- HD: hard difficult
- VD: very difficult
- HVD: hard very difficult
- S: severe
- HS: hard severe
- VS: very severe
- HVS: hard very severe
- E1-E11 (open-ended): extremely severe
The second half of the UK rating scale is a technical grade that gives a rating for the hardest move on the route regardless of how many of those moves there are on the route.
This is an open ended scale that currently starts at 4a and tops out at 7b.
Australian Grading System
The Australian or the Ewbank system was developed by John Ewbank in the 1960s. This grading system takes simplicity one step further.
Rock climb grading down under does away with letters, plus signs, and any other possible complexity—opting instead for numbers only.
The numbers start low (at 1) and go high.
For reference, the 9c listed above, is graded 39 in Australian rating.
Average climbers might climb in the 18-26 range. That’s 5c-7a+ in the French system or 5.10a-5.12a in the YDS.
The UIAA Grading System
The UIAA is responsible for setting safety standards within the climbing world.
Their free climbing grading scale was one of the earliest. Today, mostly due to the rapid evolution of climbing, it is not widely used.
Still, the UIAA scale shows up here and there, making it worth knowing as a reference point.
UIAA also uses roman numerals in a scale ranging from I-XI, with each level having a +/- incremental level.
An explanation of each level is given in the UIAA chart below:
Aid Climbing Grades
Aid climbing ratings are divided into the original rating system and what is called the ‘New Wave’ rating system.
In the original system ratings go from A0-A5 with no increments of +/- or added letters between grades.
The new wave system uses + signs starting at A2 to give another increment to the grading scale.
At times, in eaither system, you may see a C in place of A. For example A2 becomes C2.
Whereas ‘A’ stands for aid or artificial, ‘C’ stands for clean.
This is generally understood to mean the route in question can be aid climbed ‘clean.’
Meaning without the use of hammers or damaging objects like pitons or copperheads.
Original Aid Rating System
A0: Often referred to as ‘French Free,’ occasional use of gear or fixed gear to make upward progress without necessitating the use of aiders/etriers, “pulling through” small sections on fixed or secure gear.
A1: All gear is easy to place and solid with near-zero risk of falling out, generally requires the use of aiders/ertriers.
A2: Solid placements with occasional tricky or awkward placements above good gear, no fall danger.
A3: Many marginal or insecure placements in a row but still with solid placements below and low fall danger (long falls are possible but there is limited potential to fall onto a ledge or to take falls without any solid gear below you).
A4: Multiple placements in a row that hold only body weight, potential for long-unpredictable falls.
A5: Many body weight only pieces in a row with falls of 20 or more meters likely.
New Wave Aid Ratings
New wave ratings give a little more depth to help climbers be better prepared for the the journey ahead.
A1: Easy. No risk of gear pulling out/all gear should hold a fall.
A2: Moderate. Still solid gear but occasionally more difficult or awkward to place.
A2+: Potential for ~10 meter clean falls at strenuous placements but all gear below should hold a fall.
A3: Hard. Potential for ~15 meter clean falls during multiple strenuous placements in a row.
A3+: Multiple strenuous placements in a row with body weight only placements between with ~15 meter dangerous falll potential.
A4: Serious. Continually tenuous, strenuous, with multiple body weight only placements in a row and dangerous fall/ledge fall potential of ~30 meters.
A4+: More strenuous and tenuous than A4 with greater fall potential.
A5: Extreme. No placements on the entire pitch will likely hold a fall with high fall potential.
A6: A5 climbing but with marginal belays that would most likely not hold a fall.
The two common grading systems used in bouldering are the Hueco and the Font or Fontainebleau systems.
Both correspond (more or less) to their parent rating system; Hueco corresponds to YDS and Font corresponds to the French system.
The Hueco or ‘V’ scale goes from V0-V16 (currently the worlds hardest boulder problem).
Because the originators of this scale—read on to learn more—based their efforts off of John Gill’s B-system for bouldering, V0 moves are the equivalent of 5.10 climbing moves.
Unlinke the YDS, the Hueco system was actually developed in its namesake location; Hueco Tanks.
The ‘V,’ however, came from somewhere entirely different.
History Of The V-system For Bouldering
It might just be fate that ‘V’ is 5 in roman numerals and therefore corresponds to the 5.x scale of the YDS.
See, John Sherman—bouldering legend and co-inventor of the V-system—had a nickname; Verm or Vermin.
Back in the late 80s/early 90s Sherman’s group of Hueco Tanks climbers were the first cohesive North American group to take bouldering seriously.
At first, Sherman and his co-climbers didn’t even grade climbs. They used the ‘V’ scale as a measuring stick to compare their accomplishments among the group.
They were still comparing themselves to Gill’s B-system.
When Sherman wrote the first Hueco Tanks Climbing Guide his publisher at Chockstone press insisted he grade the climbs.
This moment in time is where the ‘V’ grading system used today in North America originated.
Like the YDS and French rating system, the V-system is open ended, allowing for advances in climbing ability over time.
John Gill’s B-system For Bouldering
In the 50s and 60s bouldering was seen more as a pastime or fun training for the real stuff, wall climbing.
John Gill was a climbing legend and probably even more so a legend of climbing training.
Gill was one of the first climbers to pursue bouldering as its own niche.
The B or Boulder system created by Gill had 3 levels.
B1 was considered difficult, consisting of moves equivalent to the highest level of free-climbing for the times; 5.10 trad.
B2 was considered very difficult or harder than 5.10.
B3 was reserved for limit climbs. B3 boulder problems were so hard they were only done once.
If the original ascentionsist repeated the route, it would be downgraded to B2.
For reference, some of Gill’s B2 and B3 rated boulder problems reach V10 in the Hueco scale.
Font, Bleau or Fontainebleau Ratings
Often called the Font (for English speakers) or the Bleau (for French speakers) system or even just the French Boulder system, the Font rating system originated in Fontainebleau, France.
Mountaineers were climbing in Fonatainbleau long before people in North America started taking bouldering seriously.
As a result, the Fontainebleau grading system has been around much longer than the Hueco system.
Fontainebleau grades follow a similar rating system to French free-climb ratings; a numerical grade ascending with difficulty.
In the Font system letters are appended to numbers starting with level 6.
To differentiate the Font scale from its similar French free-climbing scale, letters are capitalized in the Font system.
For example, a Font bouldering scale from easy to hardest, would look like this:
3, 4-, 4, 4+, 5-, 5, 5+, 6A, 6A+, 6B, 6B+, 6C, 6C+, 7A, 7A+, 7B, 7B+, …..8C+
Similar to the Hueco scale, the Fontainebleau scale is open ended with the highest recorded boulder climb currently at 8C+ or V16.
Other Climbing Rating Systems
The free-climb and boulder grades above account for the level of physical difficulty for a particular route.
Some types of climbing, however, involve other critical variables.
One important variable is time.
When preparing for a big mountain route or a quick alpine ascent, it is important to know approximately how long it should take to approach and climb your target route.
This time variable is represented by the National Climbing Classification System (NCCS).
The system goes by grades in roman numerals from I-VII (1-7).
Grades indicate the level of commitment required to complete the route by a “competent” team.
NCCS grades are described as follows:
- Grade I: 1-2 hours at most of technical climbing or scrambling.
- Grade II: Up to 1/2 day of technical climbing.
- Grade III: Majority of the day spent on technical climbing with an increased need for route finding and time management skills.
- Grade IV: A full day of technical climbing which may require some parties to bivouac or bail due to speed, skill set, or unforeseen circumstances.
- Grade V: Full days of technical climbing and route finding requiring at least one overnight/bivouac on route.
- Grade VI: Multiple days of technical climbing and route finding with required overnights/bivouacs on route.
- Grade VII: Remote routes with technical climbing, route finding, and bivouacs with high potential for error.
When planning a route the team must also take into consideration approach and descent time.
For example, a Grade III route requires near a full day of technical climbing on the route.
So depending on how long the approach is and how complicated the descent, a Grade III route might require overnighting at the base either on the way in, out, or both.
Alpine Climbing Grades
Due to the multi-faceted nature of alpine climbing the rating system accounts for many more factors than the time focused NCCS grades.
Specifically, Alpine ratings consider the overall commitment level and seriousness of a route based on difficulty of approach, required ascent and descent time, danger, altitude, and overall technical difficulty.
Alpine ratings are usually indicated with French letters as follows:
- F (Facile/Easy): Easy rock scrambles and/or snow slopes with possible intermittent glacier travel.
- PD (Peu Difficile/Low-Difficulty): Some technical climbing with more complex glacier travel.
- AD (Assez Difficile/Mid-Difficulty): Steep technical climbing with extensive snow and/or ice sections above 50° in angle.
- D (Difficile/Difficult): Sustained-technical climbing on rock, ice, and snow.
- TD (Tres Difficile/Very Difficult): Remote-long routes with high degrees of technicality and difficulty on multiple types of terrain.
- ED (Extrement Difficile/Extremely Difficult): Extremely high levels of technicality, remoteness, and duration on all types of terrain.
ED grades append a number for increased difficulty.
For example; ED, ED1, ED2, ED3…etc.
Ice climbing is rated with the acronym WI which stands for Water-Ice.
This implies seasonal ice versus year-around ice that is often abbreviated with AI for Alpine-Ice.
Ice climbing in the lower 48 States and most of Europe would be rated as WI.
Canadian climbers will either use the same system or drop the WI in favor of the Canadian Commitment Grade (similar to the NCCS but takes into account snow travel and danger).
Water-ice ratings are as follows:
- WI1: Low angle ice not requiring hand tools for ascension.
- WI2: Ice consistently near 60° with good protection.
- WI3: Ice consistently near 70° with multiple sections of 80-90° ice but with rests and good positioning for placing protection/ice screws.
- WI4: Ice consistently near 80° with many sections of 90° ice and occasional resting stances.
- WI5: A full rope length or long pitch of ice near 85-90° with very few rests or easy protection placements. For short pitches WI5 may signify thin or bad ice with difficult to place protection.
- WI6: A full pitch or rope length of 90° ice with no good resting positions. For short pitches this may signify more technical and steep climbing than WI5.
- WI7: Difficult, full rope length, and steep; similar to WI6 but on poorer quality ice (thin, overhanging, poorly adhered/bonded).
Putting It All Together
Now you know some of the most common ratings.
So what would this look like in a guide book or on Mountain Project?
Lets take a look at an all time classic; the Beckey-Chouinard on South Howser Tower, Bugaboos, Canada.
A guide book rating might look like this:
South Howser Tower, West Buttress, Beckey-Chouinard (IV, 5.10 or 5.9 A0, 16 pitches).
This indicates a Grade 4 route with some 5.10 climbing or 5.9 with a 5.10 move or short section that can be easily aided through on reliable gear.
You can see in the second topo the author also added the French alpine rating TD+ for Tres Difficile or very difficult.
A climber could expect a full day of technical climbing and route finding with the need to overnight/bivouac before and/or after climbing with some snow or glacial travel expected.
There are many different rock climbing rating systems in the world.
The most common free climbing rating systems are the French scale and the Yosemite Decimal System or YDS.
Both use a number and letter combination and rate climbs in ascending difficulty.
For bouldering, there are two systems: the Font or Bleau system named after the famous Fontainebleau climbing area in France, and the Hueco or V system named for John “Verm” Sherman and the Hueco Tanks climbing area in the U.S.
Another scale, the NCCS, is used in North America to indicate commitment levels of routes and the Alpine system rates climbs based on a number of factors likely encountered in an Alpine setting.
Seasonal ice is rated with the Water-Ice (WI) system.
While this is not a comprehensive list of global climbing scales, we tried to address the most commonly used rating systems.
See the chart above or download it here for a full comparison/conversion chart of the most common free climbing rating systems.
What grading scale do you use most?