The Largest Submarines in the World, Ranked (2026)

The largest submarine ever built is the Soviet Typhoon class, which displaced 48,000 tons submerged. That is more than double any American submarine, and no navy has built anything heavier since.

The catch is that every Typhoon is now out of service, the last one in February 2023. The largest submarine still in commission is Russia’s K-329 Belgorod, at up to 30,000 tons and 604 feet (184 m), the longest submarine ever launched.

This list ranks the 12 largest submarine classes by submerged displacement, the standard measure of a submarine’s size, as of October 2026. It covers boats in service, boats retired, and the two giants still on the building slip.

Rank	Class	Navy	Submerged displacement	Length	Status (Oct. 2026)
1	Typhoon (Project 941)	Soviet / Russian	48,000 tons	574 ft (175 m)	All 6 retired
2	K-329 Belgorod	Russian	24,000 to 30,000 tons	604 ft (184 m)	1 in service
3	Borei / Borei-A	Russian	24,000 tons	558 ft (170 m)	8 in service, 2 building
4	Columbia	US	20,815 tons	560 ft (171 m)	Lead boat building
5	Oscar II (Project 949A)	Russian	19,400 tons	509 ft (155 m)	About 6 active
6	Ohio	US	18,750 tons	560 ft (171 m)	18 in commission
7	Delta IV (Project 667BDRM)	Russian	18,200 tons	548 ft (167 m)	6 of 7 active
8	Dreadnought	British	17,200 tons	504 ft (153.6 m)	4 building
9	Vanguard	British	15,900 tons	492 ft (149.9 m)	4 in service
10	Triomphant	French	14,335 tons	453 ft (138 m)	4 in service
11	Yasen / Yasen-M	Russian	13,800 tons	427 to 457 ft (130 to 139 m)	5 active
12	Seawolf (USS Jimmy Carter)	US	12,139 tons	453 ft (138 m)	3 in service

1. Typhoon (Project 941): 48,000 Tons

The Typhoon displaced 23,200 tons on the surface and 48,000 tons submerged. It was 574 feet (175 m) long and an extraordinary 75 feet (23 m) wide, and carried 20 R-39 ballistic missiles and a crew of 160.

The width is the secret. Instead of one pressure hull, the Typhoon laid two long pressure hulls side by side with a third, smaller one above them, plus two more for the torpedo room and steering gear, all wrapped in one outer hull.

Six were completed and a seventh was cancelled. The Russian Navy dropped plans to modernize them in 2012, saying one upgrade would cost as much as two new Borei boats. The last one, Dmitry Donskoy, was decommissioned in February 2023, and in March 2025 Russia announced it would become a museum ship in Saint Petersburg.

2. K-329 Belgorod: Up to 30,000 Tons

Belgorod began life as an Oscar II cruise missile submarine. During construction its original 505-foot (154 m) hull was stretched to 604 feet (184 m), roughly 30 feet longer than a Typhoon, which makes it the longest submarine ever built.

Published estimates put its submerged displacement between 24,000 and 30,000 tons, so it ranks second on the upper figure and ties the Borei on the lower one. It was commissioned on July 8, 2022, with a crew of about 110.

Belgorod is a special-mission boat, not a missile submarine. It was unveiled alongside Russia’s Poseidon nuclear-armed underwater drone in March 2018, the weapon it was built to carry. With the Typhoons gone, it is the largest submarine in service anywhere.

3. Borei / Borei-A: 24,000 Tons

The Borei class is the largest submarine Russia is still building in numbers. Each boat displaces 24,000 tons submerged, measures 558 feet (170 m), and carries 16 Bulava ballistic missiles with a crew of 107.

Eight are in service as of October 2026, the newest being Knyaz Pozharsky, commissioned in July 2025, and two more are under construction. They replace several older missile submarine types at half the Typhoon’s displacement and with 107 crew against 160. Our guide to the Russian Navy in 2026 covers the rest of that fleet ship by ship.

4. Columbia: 20,815 Tons

The Columbia class will be the largest submarine the United States has ever built. The Congressional Research Service gives a reported submerged displacement of 20,815 tons, about 2,000 tons more than the Ohio class it replaces.

It is the same 560 feet (171 m) long as an Ohio but slightly fatter, at 43 feet against 42, and carries 16 Trident II D5 missile tubes instead of the Ohio’s original 24. The Navy plans 12 boats to replace its 14 Ohio-class missile submarines.

The lead boat, USS District of Columbia, was named in June 2022 and is still under construction in October 2026. As of April 2023 the 12-boat program was estimated at $132 billion to build.

5. Oscar II (Project 949A): 19,400 Tons

The Oscar II is a cruise missile submarine designed to attack NATO carrier battle groups. It displaces 19,400 tons submerged, is 509 feet (155 m) long and 60 feet (18.2 m) wide, and carries 24 P-700 Granit anti-ship missiles at up to 32 knots underwater.

Fourteen Oscar-family hulls were completed, counting the two original Oscar Is and the boat that became Belgorod. About six remain active, some being modernized. The best known is Kursk, lost in the Barents Sea on August 12, 2000.

6. Ohio: 18,750 Tons

The Ohio class is the largest submarine the US Navy has in service. Each boat displaces 18,750 tons submerged, is 560 feet (171 m) long, and carries a crew of 15 officers and 140 enlisted sailors.

Eighteen were built between 1976 and 1997. Fourteen are ballistic missile submarines, each cut from 24 to 20 Trident tubes in 2017 under the New START treaty. The other four were converted to guided missile boats carrying up to 154 Tomahawk cruise missiles each.

Those four are leaving. USS Georgia returned from its final operations in July 2026 and is due to be inactivated at Norfolk in July 2027, with Ohio, Florida and Michigan following in fiscal years 2027, 2028 and 2029. Finding boats like these is the job of maritime patrol aircraft such as the P-8 Poseidon.

7. Delta IV (Project 667BDRM): 18,200 Tons

The Delta IV is the last of the Cold War Delta family, built at Severodvinsk between 1981 and 1992. It displaces 18,200 tons submerged, is 548 feet (167 m) long, and carries 16 liquid-fueled Sineva missiles.

Six of the seven are listed as active, one of them, Podmoskovye, converted into a special-purpose boat with its missile silos removed. In the last years of the Soviet Union the class carried out Operation Behemoth, and it remains the only class of SSBN to successfully fire its entire payload of ballistic missiles.

8. Dreadnought: 17,200 Tons

Britain’s Dreadnought class will be the largest submarine the Royal Navy has ever operated. It displaces 17,200 tons, is 504 feet (153.6 m) long, and carries 12 Trident II D5 tubes with a crew of 130.

All four boats are under construction, and the first is expected by the early 2030s. They will replace the Vanguard class below.

9. Vanguard: 15,900 Tons

The four Vanguard boats have carried Britain’s nuclear deterrent since 1993. Each displaces 15,900 tons submerged, is 492 feet (149.9 m) long, and has 16 Trident II D5 tubes and a crew of 135.

They were built between 1986 and 1999 and will keep the deterrent going until Dreadnought arrives.

10. Triomphant: 14,335 Tons

France’s four Triomphant boats displace 14,335 tons submerged and measure 453 feet (138 m). Each carries 16 M45 or M51 ballistic missiles and a crew of 111.

They entered service from 1997 and can also fire Exocet anti-ship missiles while submerged.

11. Yasen / Yasen-M: 13,800 Tons

The Yasen is a nuclear attack submarine that displaces 13,800 tons submerged, more than any Western attack boat, and carries eight vertical launch silos holding four missiles each, 32 in all.

The lead boat Severodvinsk is 457 feet (139.2 m) long; the improved Yasen-M boats are shorter at 427 feet (130 m) and need a crew of just 64. Five are active as of 2026, with more on trials and fitting out.

12. Seawolf (USS Jimmy Carter): 12,139 Tons

A standard Seawolf displaces 9,138 tons submerged and is 353 feet long. The third and last boat, USS Jimmy Carter, was lengthened to 453 feet (138 m) and 12,139 tons as a Multi-Mission Platform, which puts the class on this list.

Jimmy Carter was commissioned on February 19, 2005. Only three Seawolfs were built out of 29 planned.

Near Misses: China, Virginia Block V and the I-400

China’s largest submarine, the Type 094 Jin class, displaces about 11,000 tons submerged and is 449 feet (137 m) long, with six in service according to the IISS. That is smaller than every class above, even though China has the world’s biggest navy by hull count, as our ranking of the largest navies in the world shows.

The US Navy’s Virginia Block V attack boats grow to 10,200 tons and 460 feet (140 m), which still falls short of the list.

Japan’s I-400 class, at 400 feet (122 m) and 6,560 tons submerged, was the largest submarine of World War II. Each carried three Seiran floatplanes in a deck hangar, and they stayed the largest submarines ever built until nuclear missile submarines arrived in the 1960s.

Which Is Bigger: Longest or Heaviest?

Belgorod wins on length and the Typhoon wins on displacement, and both claims are true. The Typhoon’s side-by-side pressure hulls made it about 75 feet (23 m) wide, against 43 feet for a Columbia, so it weighs far more despite being shorter.

Displacement is the better measure of size, which is why the Typhoon keeps the title. Even so, the biggest submarine is small next to the largest warships in the world: USS Gerald R. Ford displaces 101,600 tons, about twice a Typhoon.

FAQ

What is the largest submarine in the world?

The largest submarine ever built is the Soviet Typhoon class, at 48,000 tons submerged and 574 feet long. All six Typhoons are retired, the last in February 2023, so the largest submarine in service today is Russia’s K-329 Belgorod, at 24,000 to 30,000 tons and 604 feet.

What is the longest submarine ever built?

Russia’s K-329 Belgorod is the longest at 604 feet (184 m). It was stretched from an Oscar II hull during construction and is roughly 30 feet longer than a Typhoon, although the Typhoon displaces far more because it is much wider.

What is the largest US submarine?

The Ohio class is the largest US submarine in service, at 18,750 tons submerged and 560 feet long. The Columbia class now under construction will be larger, at a reported 20,815 tons, and will be the biggest submarine the United States has ever built.

How many people fit in a submarine?

It depends on the class. An Ohio-class submarine carries 15 officers and 140 enlisted sailors, a Typhoon carried 160, a Borei carries 107, and a Russian Yasen-M attack boat needs just 64.

Which country has the biggest submarines?

Russia. It built the Typhoon, the largest submarine ever, and operates the largest submarines in service today: Belgorod, eight Borei missile boats, about six Oscar IIs and six Delta IVs. The largest American class, the Ohio, ranks below all of them except the Delta IV.

Is the Typhoon class still in service?

No. Three Typhoons were decommissioned in the 1990s and scrapped, two went into reserve in 2004, and the last active boat, Dmitry Donskoy, was decommissioned in February 2023. Russia announced in March 2025 that it will be preserved as a museum ship in Saint Petersburg.

What was the largest submarine of World War II?

Japan’s I-400 class, at 400 feet (122 m) and 6,560 tons submerged. Three were completed, each carrying three Seiran floatplanes, and they remained the largest submarines ever built until nuclear ballistic missile submarines arrived in the 1960s.

What is China's largest submarine?

The Type 094 Jin-class ballistic missile submarine, at about 11,000 tons submerged and 449 feet (137 m) long. Six are in service, which makes them big by most standards but smaller than every Russian, American, British and French missile submarine class.