The Importance of the Passenger Space Ratio

When you board a cruise ship, one of the crucial factors affecting your enjoyment while onboard is how spacious the vessel feels. As you re likely going to be there for a while, you will have a view on how much personal space you enjoy. Some folks call this ‘elbow room’.

To help you choose there, are specific ratios that can guide your final decision of cruise line and cruise ship. The Passenger Space ratio is the one that highlights explicitly how much space you may expect. It is a simple ratio that relates the total volume of the ship to the number of passengers. In simple terms, it translates into how much space you can expect onboard?

By definition, gross tonnage is the measurement of a ship’s internal volume, that is, its overall interior space. The new Gross Tonnage calculation for ships determines rules and regulations, registration fees and port dues, as well as, and most importantly, to the cruise experience, the amount of passenger space available.


Gross tonnage, along with net tonnage, was adopted by the International Maritime Organization in 1969, and came into force on 18 July 1982. These two measurements replaced gross register tonnage (GRT) and net register tonnage (NRT). Gross tonnage is calculated based on “the moulded volume of all enclosed spaces of the ship” and is used to determine things such as a ship’s manning regulations, safety rules, registration fees, and port dues, whereas the older gross register tonnage is a measure of the volume of only certain enclosed spaces.

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By definition, gross tonnage is the measurement of a ship’s internal volume, that is, its overall interior space.

The measurement is, broadly, the capacity in cubic feet of the spaces within the hull and of the enclosed spaces above the deck available for cargo, stores, passengers and crew, with certain exceptions, divided by 100. Thus 100 cubic feet of capacity is equivalent to one gross ton.

It is easy to calculate and get a feel for how crowded you might feel on a particular class of ship. It is the simple ratio between the size of the vessel Gross Tonnage divided by the number of passengers. Gross Tonnage (GT) is the number used for all ships built after July 18, 1982.

The resulting magic number is called the Passenger to Space Ratio.


Passenger Space Ratio = Gross Tonnage (GT) divided by the number of passengers

The simplicity makes it is easy to compare cruise ship space ratios since these two numbers are freely available. In this way, you can easily compare like with like. Our chart below shows all the essential cruise ship ratios you need.

If we look at the actual numbers involved, Gross Tonnage is a bit of a mathematical puzzle and doesn’t have anything to do with the weight of a ship. It is a measure of all of the enclosed spaces within the vessel.  All you need to know is that it is a “fair” number that achieves a method of representing all ships of different sizes accurately.

As you don’t usually know how many passengers will be on any given cruise ahead of time, a standard number is applied. Often, this is the number of staterooms with two occupants in each, sometimes known as the ship’s capacity or double occupancy.


Finally, we can calculate the Passenger Space Ratio. It is merely the amount of space on the ship divided by the number of passengers.

Our table below shows the gross tonnage, number of passengers (double occupancy) and the calculated passenger space ratio for a selection of our favourite cruise lines.

Once you have a Ratio, you can then start to compare ships. Many will fall within a reasonably close range, and some ship design features will affect this number.

If you plan to look up the Gross Tonnage (GT) for yourself, be sure to use the Gross Registered Tonnage (GRT) and not one of the other similar numbers. These include Net Register Tonnage, Displacement, Compensated Gross Tonnage, etc.

Remember that there are several other ratios and statistics that you can use to gauge your possible cruise experience. The Crew to Passenger Ratio is one such ratio. Taken together, these can help to give an improved perspective on what you can expect on your cruise.

As a rough guide, the Passenger-to-space Ratio bands are as follows:

  • 51 and Above – Very Spacious Ships
  • 31-50 – Spacious
  • 21-30 – Not so spacious
  • 20 and under – Expect cramped conditions


Crystal Esprit Crystal 3,300 91 62 1.46 36.2
Crystal Serenity Crystal 68,870 980 650 1.51 70.27
Crystal Symphony Crystal 51,044 848 545 1.55 60.2
Queen Elizabeth 2 Cunard 90,901 2503 900 2.80 36.3
Queen Mary 2 Cunard 148,530 2620 1254 2.10 56.7
Queen Victoria Cunard 90,049 2061 981 2.10 43.7
MSC Seaside MSC 153,156 5331 1413 3.80 28.7
SeaDream I SeaDream 4,253 112 95 1.18 37.9
SeaDream II SeaDream 4,333 112 95 1.18 38.7
Seabourn Odyssey Seabourn 32,000 450 330 1.30 71.1
Seabourn Quest Seabourn 32,,000 450 300 1.30 71.1
Seabourn Sojourn Seabourn 32,000 450 330 1.30 71.1
Seabourn Encore Seabourn 40,350 604 450 1.30 66.8
Seabourn Ovation Seabourn 40,350 604 450 1.30 66.8
Seabourn Venture Seabourn 23,000 264 120 2.20 87.12
Seven Seas Explorer Regent 56,000 750 552 1.36 74.67
Seven Seas Mariner Regent 48,075 708 445 1.60 67.91
Seven Seas Navigator Regent 28,550 490 325 1.51 58.27
Seven Seas Splendor Regent 55,500 750 542 1.39 74.00
Seven Seas Voyager Regent 42,363 708 445 1.60 59.84
Silver Cloud Silversea 16,927 260 208 1.25 65.1
Silver Discoverer Silversea 5,218 124 96 1.29 42.0
Silver Explorer Silversea 6,072 144 117 1.23 42.1
Silver Galapagos Silversea 4,203 100 75 1.34 42.0
Silver Muse Silversea 40,700 596 411 1.45 68.3
Silver Shadow Silversea 28,258 388 303 1.28 72.83
Silver Spirit Silversea 39,519 608 376 1.62 65.0
Silver Whisper Silversea 28,258 388 302 1.29 72.83
Silver Wind Silversea 17,400 302 222 1.36 57.62
Star Breeze Windstar 9,975 212 153 1.38 47.1
Star Legend Windstar 9,975 212 153 1.38 47.1
Star Pride Windstar 9,975 212 153 1.38 47.1
Wind Spirit Windstar 5,350 148 88 1.69 36.15
Wind Star Windstar 5,350 148 88 1.69 36.15
Wind Surf Windstar 14,745 312 163 1.92 47.26