What Does a Rope Fall Rating Really Mean?

There are a lot of myths about what a rope fall rating means and we’re here to set the story straight. First, a higher fall rating does not signify a more durable rope. (The most common misconception.)

Overall, a higher Fall Rating does not mean a better rope. Modern climbing ropes are exceptionally reliable when well taken care of and within the 10 year material lifespan. In typical climbing situations, modern ropes are capable of handling hundreds of leader falls (and endless top rope falls) in their lifetime. There are a few exceptions which we’ll cover later in this post and we dive into deeper in our When To Retire a Climbing Rope post.

What is a Fall Rating / Number of Rope Falls?

Per the UIAA certifying body, the fall rating of a rope is the number of falls the rope can experience before failure during the rope certification test. This test attaches a weight to a section of rope that is fixed to the top of a tower and drops it.

This is a shot of Edelrid’s drop tower that is included in their extremely comprehensive Rope Handbook.

To pass the UIAA rope certification test all single ropes and half ropes (tested with a single strand of rope) must withstand a minimum of 5 UIAA falls. Twin ropes (tested as a pair) must withstand a minimum of 12 UIAA falls.

A UIAA Fall is:

• The weight is dropped for a free fall of 4.8 meters (15.75 ft) with 2.8 meters (9.19 ft) of rope; this is done to simulate an extremely bad fall, measured as a fall factor of ~ 1.7 (explained below).
• Single and Twin ropes are tested with an 80 kg (176.37 lb) weight and half ropes with a 55 kg (121.25 lb) weight.

Drops are repeated every 5 minutes until the rope fails (breaks). If it meets or exceeds 5 successful falls, the rope passes this part of the certification. This number of successful falls is recorded as the the Number of Rope Falls the rope can handle.

Fall Factor Explained

Fall factor is basically a way to explain the force that a falling climber imparts on the system by creating a ratio of the amount of rope used to the distance the climber falls. Higher fall factors mean more force felt by the gear and the climber, and lower fall factors mean the rope is able to absorb more force and keep things safer and comfier.

Falls with a fall factor of 1.7 like those used in the UIAA test rarely occur in climbing. Fall factor is calculated between 0 (falling no distance, like via a very tight top rope) and 2 (if you were on a multi pitch route and climbed above the belay anchor without placing any gear and then fell, falling the entire distance you had just climbed as well as that same distance passed the anchor before the rope caught you. So the fall distance is 2x the length of rope in the system.)

To achieve a 1.7 fall factor, you have to fall 1.7x the amount of rope that is paid out so if you were 10 meters (33 feet) above your belayer, you’d have to fall 17 meters (56 feet), which means you’d be 8.5 meters (28 feet) above your last piece of protection before the fall. Ouch. AND you’d have to do this 5 times within 25 minutes to get to the minimal 5 UIAA Fall rating. <–Highly unlikely.

Petzl created a helpful graphic and have a really wonderful post about fall factor and impact force.

In this example, if a climber climbed 10 meters up a route and fell 2 meters above their last piece of gear, they would fall a total of 4 meters; this fall factor would be 0.4. This calculation takes into consideration that there was 10 meters of rope length in the system.

This is a very reasonable fall scenario and nowhere near the forces that ropes are subjected to during UIAA testing, which is why ropes can take so many falls like this. Using this example, you can see how much more effort it would take gain a fall factor of 1.7!

Is Fall Rating the Number of Falls a Rope Can Hold?

Most importantly, the fall rating is NOT the number of falls the rope can hold in the real world. Rather, fall rating tells us that a rope can safely absorb the forces generated by a falling climber in very extreme situations.

The UIAA test created a standard that was not meant to replicate typical climbing scenarios. Instead their goal was to ensure a large margin of safety above the forces experienced in any climbing situation. By recording the number of falls (vs a pass/fail test) it provides a relative comparison across ropes, but it does not provide an absolute value of a ropes longevity.

Forces on climbing gear during falls are measured in kilonewtons (kN). We can’t stress this enough: In real world use, it is unusual for any one piece of gear to see forces much above 5kN. This 5kN is what many small cams are rated to hold. When the Black Diamond QC Lab tested dogbones to compare strength they simulated, “1000 falls of 5kN (a bit harsh but realistic) to both new and old slings.” So we can consider 5kN a baseline for rigorous testing.

So what does this mean for forces on ropes during the Fall Rating test? The impact force that Sterling reported (on a blog post that sadly no longer exists), was that the forces experienced during the Fall Rating test, “typically begin around 9kN on the very first drop and subsequent test drops on the same rope go well over 12kN.”

The increase in forces during repeated drops is not unexpected as every rope stretches out during a fall and loses its ability to absorb subsequent falls until it has had enough time to contract back to its original length. This can take days for each fall so the 5 minutes between test drops is an especially challenging scenario for ropes to handle.

Note: Fall factor and Impact Force (kN) are not directly comparable. BUT Petzl has an incredibly comprehensive post that goes over a few fall factor situations and the related impact force on the climber, belayer, and anchor (taking into consideration the climber weight, belayer weight, rope length, fall length, ropes impact force, and belay device).

This graph is Petzl’s conclusion. You can see that as fall factor increases, so does the impact force.

It’s worth noting that the forces on the anchor (gray) are the highest, while the forces on the belayer (black) are the lowest. The climber (blue) in these scenarios is experiencing forces between 2.5 – 4 kN for one fall.

From this information, it is pretty clear to see that ropes are tested at forces well above what climbers should expect to encounter.

What does a Fall Rating / Number of Falls tell us?

Unfortunately, not much other than the guarantee that, in normal climbing scenarios, your rope won’t break if you fall on it. The fall rating is simply a number that provides relative information as to the ability of a rope to repeatedly hold very harsh falls within a very controlled environment.

In reality, we are using these ropes in unique situations and environments that pose other potential dangers, i.e. sharp rock edges that can cut a rope. And this leads to the apt saying, ‘Ropes don’t break, they cut.’ Unfortunately the fall rating provides zero information about the cut-resistance of a rope. And sadly, there is no standard to measure cut resistance. Numerous manufacturers, including Edelrid, have proposed a test but as of this writing it is not yet adopted by the UIAA.

The number of falls a rope can handle does hint at the amount of dynamic elongation it has, but dynamic elongation is already a commonly reported feature that is measured separately from this test. Despite popular belief, Fall Rating also does not coincide with durability. Durability is a result of many, many variables, not the least of which is how and where the rope is being used. All the rope makers we’ve talked to consider fall ratings to be a very poor indication of a rope’s potential durability.

So although the UIAA Fall Rating test doesn’t provide consumers with a ton of useful data, it does provide a benchmark which manufacturers much reach, ensuring that you can have confidence in your ropes.

When can Ropes Break in a Fall?

The only way a dynamic climbing rope could break in a clean fall is if you exceeded the UIAA test, which would mean prior to the break there were multiple extremely hard falls within a very short timespan. This is so unlikely that we’ve never heard of it happening / have never seen any documentation of this happening.

For a rope to fail during a fall it is because it was severed/cut by running over a sharp rock or metal edge (like a worn carabiner), or rock fall. The other potential cause for rope failure is contamination by chemicals such as battery acid that decreased the strength of the nylon fibers, but this is also extremely rare.

How Many Falls Can a Rope Hold (How Long Do Ropes Last)?

How long a rope lasts has little to do with the number of falls you take. It’s really a result of varying factors including the severity and frequency of the falls your taking, what type of edges the rope is running over, what type of rock the rope is encountering, the cleanliness of your rope, if the rope is regularly getting wet, etc.

As long as your well-taken care of rope doesn’t run over sharp edges or encounter other hazards (like rock fall), modern day climbing ropes can last for hundreds of small to moderate leader falls (and endless top rope falls) in their lifetime.

As the UIAA test shows us, ropes are strong enough to fall on even in big / long falls. This is why climbers can have the confidence to take 100+ foot falls, like in this Victory Whip by Ethan Pringle without the rope breaking.