Ship Size Atlas
Compare cruise ships across major lines by gross tonnage, passenger capacity, and dimensions—then place ships side-by-side to see what "bigger" really means.
This page is built for clarity: ship size is not one number, and different sources report numbers differently. When the data is uncertain or conflicting, this atlas shows it openly.
Quick Start
Filter and Sort Controls
Ships ranked by your selected metric. Click any row to view details or add to compare.
What "Size" Means at Sea
Cruise ships are measured in several ways, and each answers a different question:
- Gross Tonnage (GT)
- A common "biggest ship" yardstick, tied to a ship's overall internal volume—not its weight. GT is the industry standard for comparing ship scale.
- Passenger Capacity
- Often reported as double occupancy (two guests per cabin) and/or maximum occupancy (every possible bed). These are not the same number.
- Length (LOA) + Beam
- Physical footprint measurements. Length overall (LOA) is bow to stern; beam is the widest point. Two ships with similar GT can feel different based on these dimensions.
- Draft
- How deep the ship sits in the water, which can affect port access and itinerary options.
When two sources disagree on a ship's specs, this atlas does not "pick a winner" quietly. It flags conflicts with badges and shows competing values.
How Size Changes the Feel of a Cruise
Ship size changes your day in practical ways—walking distance, elevator demand, venue variety, and crowd rhythm. Bigger is not automatically better. Smaller is not automatically quieter. The goal is fit.
Small (<1,000 guests)
- Easier navigation, less "sprawl"
- Often fewer venues and simultaneous options
- More intimate atmosphere
Mid-Size (1,000–2,500)
- Balanced feel: enough variety without endless walking
- Typically simpler to learn quickly
- Good compromise for mixed groups
Large (2,500–4,000)
- More dining and activity variety
- Longer walks between venues
- Busier during peak times
Mega (4,000+ guests)
- A floating "district" experience
- Maximum variety of venues and amenities
- Expect more crowd management (timing matters)
If you're deciding between two ships, compare GT, passengers, and length side-by-side—then choose the tradeoffs you can happily live with.
Methodology & Data Integrity
Confidence Labels
- Verified — Strong coverage, sources agree
- Mixed — Sources disagree or passenger typing is unclear
- Missing — Key fields not captured yet
When Sources Disagree
We show conflicts openly. The chart uses the best-supported value for sorting, but the ship drawer always shows competing values and citations.
No Plagiarism Policy
We do not copy writing, tables, or graphics from other sites. We use publicly available facts (with citations) and present them with original writing, original layout, and original visuals.
Data snapshot: v1.0.0 • Last verified: 2026-01-02
Frequently Asked Questions
What is gross tonnage (GT) and why does it matter?
Gross tonnage measures a ship's total enclosed internal volume, not its weight. It's the standard metric for comparing cruise ship "size" because larger GT generally means more onboard space for venues, staterooms, and amenities. A 250,000 GT ship like Icon of the Seas has roughly twice the internal volume of a 120,000 GT ship.
What's the difference between double occupancy and maximum passenger capacity?
Double occupancy assumes two guests per cabin (standard configuration). Maximum capacity includes every possible bed—upper berths, sofa beds, and pull-downs. A ship with 3,000 double occupancy might have 4,500 maximum capacity. Most published "capacity" numbers use double occupancy unless specified otherwise.
Which cruise ship is the biggest in the world?
As of 2026, Royal Caribbean's Icon of the Seas holds the record at 250,800 GT with capacity for over 7,600 passengers (maximum). Star of the Seas, also Icon-class, matches these specifications. MSC World Europa (215,863 GT) and Carnival Jubilee (183,521 GT) are among the other largest ships at sea.
Why do passenger counts vary between sources?
Different sources report capacity differently—some use double occupancy, others use maximum. Refurbishments can also change cabin counts. When we find discrepancies, we flag them with conflict badges rather than silently choosing one value.