By Kevin Corrigan ,

Unsent /un-sent/ 1. To have failed so badly on a route you had previously climbed that you negate your redpoint. 2. A humor column.

Numbers. Letters. Symbols. Roman numerals. To the uninformed, rock climbing grades appear to be a seemingly impenetrable code. But those people are only half right. Climbing grades do mean something. Read the primer below to get yourself up to speed, then cut it out and post it in your local gym with or without their permission.

## The Yosemite Decimal System

Most rock climbs over 20 feet tall in the U.S. are graded using the Yosemite Decimal System (YDS). A YDS grade is split into two numbers separated by a period and looks like this:

### Class

All climbing grades begin with the number five. This is the class. It’s used to let you know that you are on a real rock climb and not a scary hike. If the number is less than five, you are not rock climbing. Go back to the ground and start over.

### Difficulty

The number after the decimal suggests how hard a climbing route is. Grades 5.10 and above are broken down into a, b, c, and d, and all grades can receive plus or minus notations, and grades 5.10 and above are broken down into a, b, c, and d. All these are designed to make climbing grades more descriptive and easier to understand, but note that the chart is not linear. It is arranged in order of true difficulty below.

*Prior to 1961, numbers above 9 had not yet been invented. The 1960 5.9 grade encompasses modern 5.9 to 5.15c.

### Older Routes

Most routes graded in the 1960s received ratings much easier than what we’d consider them today. This is because the Golden Age climbers were always drunk or stoned and had little grasp of reality. To find accurate assessments of these routes, browse the comments on Mountain Project and ignore any that call the route “a good warm-up.”

The Hueco Scale

Bouldering grades fall under the Hueco Scale, aka the V Scale, and look something like this:

### Letter

Every bouldering grade begins with a V. Why? Because boulderers are shaped like V’s, with broad shoulders and very skinny legs that come to a point at their feet. In fact, if you draw a little face on a V and squint your eyes, it looks just like bouldering pioneer John “Vermin” Sherman.

### Number

A combination of digits used to denote difficulty. Most employed people who started climbing after college can ignore anything above V9.

Though crack climbs are given YDS grades, all crack climbs can be broken down to one of three unofficial grades: Easy, Painful, and Impossible. If you are an adept crack climber, the rough equivalents are:

5.0-5.11: Easy
5.11-5.13: Painful
5.13 and up: Impossible

If you are not a crack climber, the scale will look more like this:

5.0 and up: Painful and Impossible

## Protection Rating

Some routes receive extra letters at the end that look similar to movie ratings (PG, PG-13, R, X). Unfortunately, these have nothing to do with the amount of bare breasts or sex you will encounter on a climb. They align more with the violent side of movie ratings. The worse the rating, the more blood and gore your belayer will witness if you fall. Think of them like this:

G: A safe route that everyone can enjoy.

PG: Pretty safe, maybe be careful above that one ledge.

PG-13: Appropriate for most climbers, but avoid if your belayer is sensitive to swearing.

R: Do not fall off this route in the presence of children under the age of 18 or anyone sensitive to blood or screaming. Really just don’t fall.

X: Don’t bother with these routes unless you think unnecessarily risking your life provides you with some kind of spiritual experience, or the route is way below your usual onsight level.

Many countries have their own unique grading systems. In the time it would take you to learn about these, you could eat an entire baguette and download an app that converts them to YDS. Just do that.

We hope you have a basic understanding of climbing grades now. Remember: They’re all subjective, influenced by the height, weight, strengths, weaknesses, ape index, technical ability, whims, bias, hunger level, and blood alcohol content of the first ascensionist, and are therefore meaningless. Ignore them and climb whatever looks fun.