Larry Slawson received his master's degree at UNC Charlotte. He specializes in Russian and Ukrainian history.
The 10 Most Powerful Nuclear Bombs
- RDS-220 Hydrogen Bomb—"Tsar Bomba" (50 Megatons)
- B41 (25 Megatons)
- TX-21 "Shrimp" (14.8 Megatons)
- Mk-17 (10 to 15 Megatons)
- Mk-24 (10 to 15 Megatons)
- "Ivy Mike" H-Bomb (10.4 Megatons)
- Mk-36 (10 Megatons)
- B53 (9 Megatons)
- Mk-16 (7 Megatons)
- Mk-14 (6.9 Megatons)
10. Mk-14 Nuclear Bomb (6.9 Megatons)
The Mark 14 Nuclear Bomb (also dubbed the Mk-14 or TX-14) was an American thermonuclear weapon designed in the 1950s and was the first solid-fuel staged hydrogen bomb in the world. As an experimental weapon, the United States only produced five of these bombs by 1954, testing the device in April of that year during the “Castle Union” nuclear experiment.
“Using a non-radioactive isotope of lithium,” the nearly 18-foot long bomb was designed to be delivered by either B-36 or B-47 bombers (due to its substantial weight of 31,000 pounds). It employed a parachute-drop method to decelerate its fall to the earth (www.army-technology.com).
During the Castle Union Nuclear test, the Mk-14 was successfully detonated with a yield of 6.9 megatons. In terms of size, the Mk-14 was approximately 328 times more powerful than the atomic bomb (“Fat Man”) dropped over Nagasaki in 1945. Despite successful tests, the Mk-14s were retired later in the year because 5 megatons of its total power were derived from fission reactions.
As a result, the weapon was considered very “dirty” (referring to the tremendous amount of radiation dispersed from the device after detonation). In response, all five Mk-14s were recycled and used to construct the larger, more effective Mk-17 variants by 1956.
9. Mk-16 Nuclear Bomb (7 Megatons)
The Mark 16 Nuclear Bomb (also referred to as the Mk-16, TX-16, or EC-16) was a large thermonuclear weapon based on the Ivy Mike Hydrogen-Bomb. The weapon was the only thermonuclear bomb ever developed to use cryogenic deuterium fusion fuel.
Due to the number of vacuum flasks required for this type of fuel, the bomb was extraordinarily large, weighing 42,000 pounds with a length of nearly twenty-five feet. As a result, a specially modified B-36 was the only American aircraft capable of deploying the weapon.
Despite being manufactured in January 1954, the bombs were retired by April of that year due to successful tests of solid-fueled nuclear weapons, notably the Mk-14s. Although tests of the Mk-16 were planned to take place during Operation Castle, the success of Castle Bravo’s “Shrimp” device made the Mk-16 relatively obsolete in the eyes of the American military.
Nevertheless, current estimates place the Mk-16 series of bombs in the top ten most powerful nuclear weapons ever developed due to their expected yield of 7-8 megatons (approximately 333 times more powerful than the “Fat Man” detonation over Nagasaki).
8. B53 (Mk-53) Nuclear Bomb (9 Megatons)
The B53 (also known as the Mark 53) was a “bunker-buster” thermonuclear weapon developed by the United States military during the 1960s. The bomb was first designed in response to the deep underground bunkers constructed for Soviet leaders during the Cold War.
Using a surface blast to collapse the surrounding earth onto its target, the bomb was designed to inflict massive damage on underground centers, giving the United States a decisive edge in the event of nuclear war.
Although much smaller than nuclear bombs from the 1950s (weighing 8,850 pounds and measuring just over 12-feet in length), the bomb had a far greater yield of 9 megatons. At this yield, a B53 detonation could destroy all structures within a 9-mile radius, with severe burns possible as far as 20-miles. Depending on terrain, researchers believe that casualty rates within 2.25 miles of the blast would be in the vicinity of 90-percent.
Over 340 B53s were developed during the 1960s, with fifty of these bombs being transferred to the Titan projects that incorporated the W-53 nuclear warhead (based on the B53’s specifications). The final B53s were dismantled during 2011 after numerous safety concerns were raised concerning their security and containment.
7. Mk-36 Nuclear Bomb (10 Megatons)
The Mk-36 nuclear bomb, also known as the Mark 36, was a high-yield thermonuclear weapon first developed in the 1950s. Using a multi-stage fusion system comparable to the Mk-21, the Mk-36 was considered the first “dry” nuclear weapon tested by the United States government.
In total, the massive Mk-36, which measured over 150 inches long and weighed nearly 17,700 pounds, could deliver a total yield of 10 megatons upon detonation. Using two separate parachutes, the bomb was designed to be airdropped slowly over its target to give bomber crews enough time to escape potential harm.
In total, the United States military developed over 940 Mk-36 bombs between 1956-1958, with two separate versions being developed, including the Y1 and Y2, respectively. However, as with most of the United States’ early nuclear weapons, the Mk-36 was quickly retired by 1962, being replaced by the far more powerful (and destructive) B41 devices.
6. "Ivy Mike" H-Bomb (10.4 Megatons)
The “Ivy Mike” H-Bomb (Hydrogen Bomb) was a thermonuclear weapon first detonated on 1 November 1952 by the United States on Enewetak Atoll. Designed by Richard Garwin, the bomb was incredibly massive, with a total length of 244 inches (6.19 meters) and a total weight of 82 tons. Following detonation, Ivy Mike produced a total yield of 10.4 megatons, creating a fireball with a 2.1-mile radius.
The explosion was so powerful and violent that the bomb’s mushroom cloud rose to an altitude of 56,000 feet in less than 90 seconds (reaching a maximum height of 135,000 feet). Radioactive debris was reported falling nearly 35 miles away from the blast site, while radioactive fallout remained for several months.
The explosion also created two new elements known as einsteinium and fermium, which were produced around the detonation site due to the bomb’s highly concentrated neutron flux. In terms of destructive power, the “Ivy Mike” was approximately 472 times more powerful than “Fat Man,” which was detonated over Nagasaki in 1945.
J. Robert Oppenheimer Quote
"If atomic bombs are to be added as new weapons to the arsenals of a warring world, or to the arsenals of nations preparing for war, then the time will come when mankind will curse the names of Los Alamos and of Hiroshima."
— J. Robert Oppenheimer
5. Mk-24 / B-24 Nuclear Bomb (10–15 Megatons)
The Mk-24, also known as the B-24 or Mark 24, was a massive thermonuclear weapon developed by the United States military between 1954 and 1955. Approximately 105 of these devices were constructed in less than a year and were based (in design) on the Castle Yankee series of bomb tests.
As the third-largest nuclear bomb (in size) ever constructed by the Americans, the bomb itself was massive, measuring over 296 inches long and weighing over 42,000 pounds. Although never officially tested by the government (except for a prototype device in 1954), researchers believed that the bomb possessed an overall yield of 10-15 megatons as the Castle Yankee test (similar design) yielded 13.5 megatons upon detonation.
Due to this destructive capability, a 64-foot parachute was specially designed for the Mark 24 to slow its descent and allow bomber crews ample time to escape its blast radius. Although decommissioned soon after its development, a surviving Mark 24 casing remains on display at the Castle Air Museum in Atwater, California to this day.
4. Mk-17 Nuclear Bomb (10–15 Megatons)
The Mark 17 nuclear bomb (also known as the Mk-17) was the first mass-produced series of hydrogen bombs developed by the United States military in 1954. Although phased out in 1957 (due to larger, more efficient prototypes in development), the Mk-17 was an extremely powerful weapon with a yield approaching 15 megatons.
The Mk-17 was well-known for its weight and size, measuring over 41,500 pounds, with a length of over 7.52 meters (24 feet, 8 inches). Approximately 200 Mk-17s were developed between 1954 and 1955, along with several modified B-36 Bombers explicitly designed for the bomb’s particularities.
Like many bombs on this list, a 64-foot parachute was also specially designed to delay the bomb’s descent to earth, giving bomber crews time to escape the blast radius and initial shockwave upon detonation. With the creation of smaller (and more easily transportable) bombs in the late 1950s, the Mk-17 was phased out in 1957.
Five of the casings from the Mk-17 can now be observed, first hand, at various Air Force museums across the country, including the Castle Air Museum (Atwater, California) and the National Museum of Nuclear Science & History (Albuquerque, New Mexico).
3. TX-21 "Shrimp" (14.8 Megatons)
The TX-21 nuclear bomb, also known as the “Shrimp” Thermonuclear bomb (or Castle Bravo), was a weapon first tested on 1 March 1954 at Bikini Atoll in the Marshall Islands. Housed in a cylinder weighing nearly 23,500 pounds and measuring over 179.5 inches in length, the massive bomb was originally designed as a 6 megaton weapon that used lithium deuteride to power its fission reaction.
However, due to errors encountered during its design by Los Alamos National Laboratory, the explosion at Bikini Atoll was nearly three times the predicted yield, generating nearly 15 megatons of destructive force (approximately 1,000 times more powerful than the atomic bombs used on Japan during the Second World War). Within one second (after its detonation), the nuclear weapon formed a 4.5-mile wide fireball visible over 250 miles away.
The characteristic mushroom cloud (common in nuclear blasts) reached 47,000 feet in less than a minute, with an overall width of 7-miles. Nearly 7,000 square miles of the surrounding Pacific Ocean were contaminated with radioactive debris. Areas such as Rongerik, Utirik, and Rongelap were among the areas most affected by the falling matter.
Due to high winds during the test, radioactive substances were also found as far away as Southeast Asia, Australia, Europe, and the Southwestern United States for several weeks following the blast. Unanticipated fallout and radiation created an international incident in the following weeks, as thousands of individuals were affected by various levels of radiation sickness (including nausea, diarrhea, hair loss, skin lesions, and vomiting).
Although the TX-21 was not the largest nuclear bomb designed by the American military, it remains the largest nuclear test ever carried out by the United States
2. B41 Nuclear Bomb (25 Megatons)
The B41 Nuclear Bomb, also known as the Mk-41, was a three-stage thermonuclear weapon designed by the United States during the early 1960s. As the most powerful bomb ever constructed by the Americans, the maximum yield of the device was estimated to generate nearly 25 megatons of destructive force upon detonation. Employing deuterium-tritium as its primary, along with lithium-6 enriched deuteride for its fuel source, the B41 utilized nuclear fusion to create its massive yield.
The B41 measured over 12-feet long (3.76 meters), weighed over 10,670 pounds, and was designed to be carried by the massive B-52 Stratofortress and B-47 Stratojet (with or without parachute delivery). Nearly 500 of these massive bombs were developed between 1960 and 1962, before finally being retired in July 1976 (following its replacement by the B53).
Despite being smaller (in yield) than the most powerful bomb on our list, researchers argue that the B-41 was the most efficient thermonuclear weapon ever designed in history, maintaining the highest yield-to-weight ratio of any weapon created. In terms of power and destructive capabilities, the B-41’s yield was approximately 1,136 times more powerful than the atomic bombs detonated in Japan during the Second World War.
1. Tsar Bomba (50 Megatons)
The RDS-220 Hydrogen Bomb (Affectionately dubbed the “Tsar Bomba”) was the most powerful nuclear bomb ever built and was detonated by the Soviet Union on 30 October 1961 over Novaya Zemlya, just north of the Matochkin Strait. Delivered by a modified Tu-95V Soviet bomber, the bomb weighed approximately 27 metric tons (59,520 pounds) and was twenty-six feet long by 7 feet wide.
Due to its tremendous size and destructive power (50 megatons), a special parachute was constructed to slow the bomb’s descent to Earth, giving the bomber crew time to fly approximately twenty-eight miles away before the Tsar Bomba detonated. Unbeknownst to the crew, however, Soviet scientists gave the pilots only a 50-percent chance of actually surviving the blast once detonation occurred.
At 11:32 PM, the Tsar Bomba was dropped from an altitude of 34,500 feet and detonated approximately 4,000 meters aboveground. The nuclear blast (possibly reaching a yield of 58.6 megatons) was so powerful that shock waves were felt over 127 miles away by an observation aircraft (a Soviet Tu-16). Although the Tu-95v bomber crew survived the blast, the shockwave caught their aircraft seventy-one miles away, nearly downing the plane.
An experimental American aircraft, known as the KC-135R, was also in the area during the test and was scorched by the blast, nearly killing the pilot on board. Following its detonation, the Tsar Bomba could be seen over 620 miles away and created a 5-mile wide fireball along with a 42-mile high mushroom cloud (seven times the height of Mount Everest) that reached Earth’s mesosphere.
Researchers discovered, to their amazement, that the bomb’s shockwaves reached distances of 560 miles, shattering windows as far away as Norway and Finland. The heat from the explosion was also capable of causing third-degree burns as far as sixty-two miles away (100 kilometers).
Despite the bomb’s tremendous power, Soviet scientists had actually diminished the Tsar Bomba’s yield significantly by removing its uranium-238 tamper before delivery. Original yields for the Tsar Bomba were calculated to be 100 megatons. However, due to the threat of extreme nuclear fallout and the near certainty that the bomb’s delivery crew would be killed following detonation, steps were taken to diminish the Tsar Bomba’s capabilities. Nevertheless, the Tsar Bomba remains the single most deadly (and powerful) nuclear device ever detonated on Earth.
How Powerful Is the Tsar Bomba?
“Complete List of All U.S. Nuclear Weapons.” List of All U.S. Nuclear Weapons, n.d. https://nuclearweaponarchive.org/Usa/Weapons/Allbombs.html.
Nuclear Weapons: Who Has What at a Glance | Arms Control Association, n.d. https://www.armscontrol.org/factsheets/Nuclearweaponswhohaswhat.
Praveen. “The Biggest and Most Powerful Nuclear Weapons Ever Built.” Army Technology, March 31, 2014. https://www.army-technology.com/features/featurethe-biggest-and-most-powerful-nuclear-weapons-ever-built-4206787/.
“We Visualized Every Nuclear Weapon in the US Arsenal.” Union of Concerned Scientists, n.d. https://www.ucsusa.org/nuclear-weapons/us-nuclear-arsenal.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
Questions & Answers
Question: How many nuclear bombs have been dropped in the world?
Answer: As of 2020, approximately 2,746 nuclear devices have been dropped (or fired) by the various world governments. These tests include underwater, atmospheric, traditional, and underground detonations. To date, the United States and former Soviet Union have conducted the most nuclear bomb tests with 1,132 and 981, respectively.
© 2019 Larry Slawson
David on July 02, 2020:
If the tsar bomba were to be utilised at its maximum capacity it could potentially cause a five year long winter and if detonated in especially windy areas cause a devastating wave of cancer ARS and genetic mutations and possibly in the right conditions end around half of humanity
Jonny on August 18, 2019:
The Tsar Bomba was estimated to be capable of achieving 100 megatons but was not tested with this capability due to the insane risks with that quantity of fallout
Larry Slawson (author) from North Carolina on August 15, 2019:
I agree Miel! Haha. Scary to think that bombs like this exist.
Miel Reyes from Philippines on August 15, 2019:
And all the while I thought the B41 nuclear bomb was the most powerful in history! And I hope nothing exists as more powerful than the Tsar.
Larry Slawson (author) from North Carolina on August 13, 2019:
I agree, Liz! Makes me wonder what other types of nuclear weapons may exist (that we know nothing about haha).
Liz Westwood from UK on August 13, 2019:
These are frightening weapons. The level of potential destruction and devastation is mindblowing. I just hope they are not called into play in a war situation.