A rope designed for rock climbing is dynamic (not static), meaning it can stretch and absorb the energy of a falling climber to reduce the impact force, preventing injury like a broken back. Climbing ropes are made of nylon and they come in various diameters and lengths. Climbing ropes are engineered to be incredibly strong to withstand any likely (or unlikely) climbing scenarios.

Below we’ll give you an overview of all the things to know about climbing ropes (with many resources and options to dive in further).

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Most climbers first encounter climbing ropes in climbing gyms, where they learn to safely tie-in, belay, and lower a climber.


The important part to know about rope construction is that the core provides the rope’s strength, while the sheath protects the core from abrasion and damage.

All ropes that are made, tested, and certified (by the UIAA/CE) for recreational climbing are extraordinarily strong and will not break in a normal (or even abnormal) climbing situations, for a human climber of any size. A climbers body would not be able to withstand the forces required to break a climbing rope. That said, ropes can wear out, in which case they would have reduced strength. We have a post detailing how long climbing ropes last and a post on the signs it’s time to retire a rope.

Although ropes come with a “fall rating” that is between 5 (the minimum to be certified) and 50 (currently the highest, there is no max), this is not the number of regular climbing falls a rope can withstand before it fails. It is specific to some very strict testing standards, that would be impossible to repeat naturally in the real world. You can read details of fall ratings and how they’re tested in this post.

Rope Types

Although there are 3 rope types certified for climbing (single, twin, half/double), the vast majority of ropes sold and used in the US are rated as a single rope.

3 Climbing Rope TypesA “single” rope means that only one, single rope, is used at a time. In twin and half/double scenarios, two ropes are used at a time – and this is only done outside, on meandering routes to reduce rope drag, or to add a redundancy like while ice climbing.

Some ropes can be certified for more that one type (some are certified for all 3 types!). Rope certifications are always on the packaging and also printed at the end of the rope.

An example showing the rope type icons that are seen on rope end markers. Left: A single rated rope. Middle: A half rated rope. Right: A triple rated, single/half/twin rope.

Rope Diameter and Length

The two largest decision factors in choosing a rope are the length and diameter.

The most common length of rope for indoor climbing is 40-50 meters (50 meters is less likely, but some very tall gyms require it). Outside, the most common diameter used is 60m though some climbers choose 70m if they are eying some long routes and/or want to connect two pitches together while climbing outside. Besides those most common use cases, there are more options and scenarios that we cover in our rope lengths post.

For diameter, climbing ropes technically range from 7 mm to 11.5 mm. Although this doesn’t sound like a lot (less than a quarter inch!), the difference feels significant. Today, the majority of ropes that are bought for rock climbing range from 9 mm – 10 mm, so the nuances are even smaller, but important.

In general smaller diameter ropes will be lighter and more pliable, while thicker diameter ropes can offer more durability (as they use more rope fibers). Thicker ropes will also add more friction while belaying which many climbers find to be helpful for controlling the rope. Gym’s typically use ropes that are 10.5 – 11mm in diameter. We go over all the rope diameters and where and why they’re used in this rope diameter post.

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Most gyms use burly 10-11mm ropes for top rope climbing because the extra girth makes them extra durable to hold up to a ton of use.

Rope Dry Treatment

Ropes look the same whether they have dry treatment or not. They do not feel the same, though. Dry treated ropes will feel much smoother and slicker, and they will run through a belay device much faster. Dry treatments were originally designed for mountaineers, ice climbers, and alpinists who are always climbing in wet conditions.

Climbing in the gym, there is minimal reason to pay more money for dry treatment. The real benefits of a dry treated rope is when a climber is mountaineering, ice climbing, or climbing in wet environments. Otherwise, a climber may also choose a dry treated rope to help repel dirt and sand, like when climbing in sandy areas Red Rocks or Moab.

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Dry ropes can have dry treatment on the core or the sheath. UIAA Certified Dry ropes must have BOTH the core and the sheath treated to ensure it absorbs less than 5% of its weight in water (you can read all the test details in this post).

Protip: Dry treatment does wear off. If you buy a dry rope to use in wet conditions, don’t use it to climb on dry rock. When the rope slides against the rock, it will start to wear off the dry treatment. 

Protip: When indoors and out, to increase the longevity of your rope, always use a rope tarp or rope bag. Inside, you’ll avoid chalk particles, and outside you’ll avoid dirt/grime/sand.

Middle Marks

Middle marks are any marking that makes the middle of the rope obvious. A middle mark is a rope features that is most easily visible. They are not necessary in a gym setting and they often increase the price (particularly the complicated bipattern and bicolor designs).

Some ropes have no middle markings (especially if the length is below 50 meters). Many ropes have a simple black marking, and others have a more technically complicated color or pattern change.

A black middle mark:


Bicolor and bipattern middle markings can look identical – the only difference is the construction method. 

The left rope looks like it has a pattern change and would be a bipattern rope BUT bicolor and bipattern designs can have the same effect looks wise, as the difference in name is in the construction.


Finding the middle of the rope is most important while rappelling to ensure you have the center of the rope through the anchors. When the rope is centered for a rappel you know there are two equal rope lengths to rappel from, ensuring that you won’t rappel off one of the ends. Sadly, rappelling off the end of the rope is one of the most common climbing accidents (this is also why you should ALWAYS tie a knot at the end of the rope ends when rappelling).

Rope Elongation

Dynamic and static elongation sound really technical and they aren’t talked about that much, but it’s one feature that can make a huge difference in the climbing experience. Less static elongation is really helpful for providing a particularly tight top rope belay. More dynamic elongation is helpful for softer (and further) lead fall catches.

It can be really hard for a belayer to create a tight top rope if they’re using a rope with high static and dynamic elongation. When the climber rests and goes hands off mid-climb, they can easily “fall” below the move they were currently at, even if the belayer is keeping a tight top rope. This is not the fault of the belayer but the ropes stretching characteristics.

Similarly frustrating, a belayer with good belaying technique, could have a frustrated lead climber when they’re using a rope with low dynamic and static elongation. The climber could blame the belayer for not providing a soft catch, when the issue is more that the rope is not very stretchy and is making it much harder to have the expected experience. They belayer can try to accommodate for the lack of stretch, but it will be harder than with a rope with higher elongation rates.

The elongation percentages aren’t always listed on the packaging (boo!) but we do list the elongation rates for all ropes on WeighMyRack, within the technical specifications and on the comparison page.

Elongation is just one of the many specs we capture on every rope we list on WeighMyRack

Dynamic vs Static Clarification

Early in this post we said dynamic ropes are used for climbing. This is absolutely true. Static ropes are sometimes used by climbers to assist in other climbing-related situations. For example, routesetters sometimes ascend static ropes or haul with static ropes. Outside, big wall climbers and aid climbers also haul gear and ascend lines with static ropes. Static ropes are never used in a situation where the climber may fall on the rope, as they incredibly high impact forces that could seriously injure the climber.

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Route setters use ropes that do not stretch called static ropes for things like hauling and ascending walls when they are putting holds and volumes on the wall.

Helpful and Important Climbing Rope Facts

  • All dynamic climbing ropes are more than strong enough for all sizes of climbers.
  • All ropes used in the gym and most ropes used outside in the US are rated as single ropes, climbing with only one rope at a time (even while rappelling, you are often using 1 rope, doubled over).
  • Rope length and diameter are two of the biggest deciding factors for buying a rope.
  • Dry treatment is a luxury add-on that is most helpful for people climbing in snow and ice. If price isn’t your biggest concern, it can also be helpful to repel dirt/sand/chalk.
  • UIAA certified dry ropes are guaranteed that both the sheath and core dry treated for maximum protection while climbing on snow and ice.
  • Middle marks are most helpful for climbers who will rappel and who need to know where the middle of the rope is located.
  • Higher dynamic elongation = softer (and further) lead falls.
  • Less static elongation = tighter top rope belays.
  • Static ropes are NOT used for rock climbing when a climber could take any size of fall – they are only used for climbing-adjacent tasks like ascending a rope or hauling (like by routesetters).