# Calculating Passenger Space Ratio

**by Paul Motter**|

**01.10.12**

**Exactly how useful is this industry standard? In some cases not useful at all.**

I just wrote an article discussing the passenger/space ratios of various ships. I have always found this particular statistic to be somewhat dubious, but now I think it can be plain misleading. |

Passenger/Space ratio is supposed to represent the amount of space "per passenger" on a cruise ship, and is merely a method to indicate how crowded a ship will feel during a cruise.

Now, to me the easiest way to see if a ship is too crowded is to order an omelet. If I had to stand in line for ten minutes just to place the order then that ship is too crowded.

I am happy to say that most cruise ships are not too crowded at all. Even Royal Caribbean's Oasis of the Seas, one of the world's largest cruise ships, never felt crowded to me. A well-designed ship is able to manage crowd flow easily, and so "passenger space ratio" really boils down to a bragging point more than anything else.

But the more I look the more the statistic seems merely supercilious. In my article I used a source which calculated the PSRs based on full capacity. But I just got an email from a self-appointed cruise ship specification enforcement officer (sorry, that is just a joke) that says I was wrong to calculate PSR of a cruise ship based on full capacity - because the industry standard is to always use berth capacity.

So - let's just take a look at Passenger Space Ratios - as an industry standard...

First of all, PSR starts by taking the total gross tonnage of the ship - actually a method of measuring the ship's internal open space in square meters. Gross tonnage has nothing to do with the actual weight of the ship - it is a measure of empty space, much like saying a "one-gallon bucket." In fact, a cruise ship has thousands of internal compartments (unlike a bucket) and so the internal empty volume of two similarly-measured gross tonnage ships could look and feel vastly different.

Further complicating the matter, in fact only a certain percentage of that open volume is accessible by the passengers. The GRT measurement of any ship also includes crew decks, the engine rooms and even inside the insides of smokestacks. Not really a useful representation of "space per passenger," right? In one case the actual GRT of a ship was changed after it was discovered they had included the balconies.

And even furthering complicating the matter - as an industry standard, PSRs are calculated using berth capacities, not full capacities of ships.

What is the difference? Berths are loosely defined as "permanent beds" and in almost all cases a stateroom is sold as "double occupancy" meaning each stateroom has two berths and accommodates two people. "Berth capacity reflects two people per stateroom, while "full capacity" reflects the total number of passengers a ship can carry.

Every cruise ship has several cabins with the facility to sleep an additional third, fourth or even fifth passenger. Most cruise ships sail at above their berth capacity on every cruise - the average figure industry-wide is closer to 104% capacity.

This person was kind enough to do some math for me and told me that the new Carnival Dream has a berth capacity of 3690 people, giving it a PSR of 35.23. But the full passenger capacity of the same ship is 4891, making the full capacity PSR 26.6. That would be considered a pretty dismal PSR in the cruise industry today, but fortunately Carnival ships rarely sail at completely full capacity.

But one ship this particular person called me out on is the new Disney Dream. This ship has a berth capacity of 2500 people. This is for double occupancy. But this is one ship obviously designed for families and almost every stateroom has extra pull-down or sofa-beds for the kids. In most cases there are two adults filling the berths and the kids take the extra beds. Some Disney staterooms can even sleep five people, although three or four is most common.

It was pointed out to me that using the "industry standard" berth capacity Disney Dream has a Passenger Space Ratio of 51. Well, 51 is a relatively high PSR, putting the ship in a league with very upscale ships. But in this case that would be a ridiculous way to describe this ship, since it is purposely designed to sleep far more than its berth capacity. I had written its PSR at 32 - based on its full capacity of 4000.

Obviously, you have to pick one or the other, berth capacity or full capacity. It does not make sense to mix them. But which is more accurate?

My friend then told me Disney Dream averaged 3800 people per cruise - just 200 people short of full capacity - for that last six months. He went to say that translates to an occupancy rating of 150.7% full.

What? To me - 3800 is 95% of full capacity of 4000, just 5% short of being completelly full, so somehow saying 150% just seems wrong. But when PSR is calculated based upon berth capacity, in this case 2500 berths, that infers the extra 1300 people are just 50% (or so) over the 100% full berth capacity. This pretty much renders Passenger/Space ratio another meaningless statistic, right?

As long as you have a standardized method - and as long as you know the berth capacity and full capacity for every ship, it has its own specific logic, and there is nothing wrong with having industry standards.

But let's be honest, is these really the best ways to calculate or represent ship space ratios? A ship that holds 4000 people that sails with an average of 3800 people onboard is actually sailing at 95% capacity, not 150%, right? Furthermore, the "average" PSR using the actual average figure (3800) is 33.6.

So, I said 32, and I was wrong according to industry standards, but I am being told the correct figure is 51. Um, who is closer to the actual PSR based upon average capacity in the last six months?

Okay - I will admit, I don't know the average capacity for every ship I mentioned, and it would be nice if such information was made more readily available, but at least I know one thing - Passenger Space Ratio as a way of comparing cruise ships is an even more misleading than I originally thought.