The U.S. Army remains the largest branch of the American military, with 449,344 active duty personnel in 2023. While the Army leads in numbers, the newly established Space Force had just 8,879 active duty members, highlighting the evolving nature of modern warfare and the increasing importance of space-based capabilities. Confidence in military remains high Despite fluctuations in force size, public trust in the U.S. military remains strong. In 2024, 61 percent of Americans expressed a great deal or quite a lot of confidence in the armed forces, a slight increase from the previous year. While a slightly higher share of Republicans have shown more confidence in the military, trust in the institution remains high across party lines. Global commitments The United States continues to invest heavily in its military capabilities, with defense spending reaching 916.02 billion U.S. dollars in 2023. This substantial budget supports not only domestic defense needs but also enables the U.S. to respond to global crises, as evidenced by the over 40 billion euros in military aid provided to Ukraine following Russia's invasion. The high level of spending, which translates to about 2,220 U.S. dollars per capita.

There were 449,344 active duty U.S. Army members in 2023. This amount represents a slight decrease in comparison to the number recorded in the previous year. Overall, there were 1.27 million active duty U.S. Department of Defense members, including officers and enlisted personnel in 2023.

The graph illustrates the number of personnel in each branch of the U.S. Military for the year 2025. The x-axis lists the military branches: Army, Navy, Marine Corps, Air Force, Space Force, and Coast Guard. The y-axis represents the number of personnel, ranging from 41,477 to 449,265. Among the branches, the Army has the highest number of personnel with 449,265, followed by the Navy with 333,794 and the Air Force with 317,675. The Marine Corps and Coast Guard have 168,628 and 41,477 personnel, respectively. The data is displayed in a bar graph format, effectively highlighting the distribution of military personnel across the different branches.

Historical chart and dataset showing U.S. military size by year from 1985 to 2020.

In the United States, active duty Armed Forces personnel tended to be young, with the majority under the age of 30 years old. In 2023, there were 546,361 U.S. Defense Armed personnel aged 25 and under. In the age group 26 to 30, there were 275,756 Armed Forces personnel.

In 2023, there were around 1.11 million active duty U.S. Armed Forces personnel stationed within the United States. In that year, there were 156,418 U.S. Armed Forces personnel stationed in California, the most of any state.

At the end of the fiscal year of 2024, it is estimated that there will be ** Generals serving the United States Army, and a total of ******* enlisted personnel. Military personnel The military departments in the United States are: the U.S. Army, the U.S. Navy, the U.S. Air Force, the U.S. Marine Corps, and the U.S. Coast Guards. The President of the United States is the military’s overall head and forms the military policy with the U.S. Department of Defense. The U.S. military is one of the largest militaries in term of number of personnel. The largest branch of the United States Armed Forces is the United States Army. The United States Army is responsible for land-based military operations. The active duty U.S. Army personnel number has decreased from 2010 to 2021. In 2010, there were ******* active duty U.S. Army members, as compared to ******* in 2021. The number of active duty U.S. Navy personnel has decreased slowly over the past 20 years. In 2021, there were ******* active duty Navy members in the United States Navy. The United States Navy personnel are enlisted sailors, commissioned officers, and midshipmen. Sailors have to take part in Personnel Qualification Standards, to prove that they have mastered skills. The United States Air Force is the aerial warfare service branch of the United States. The active duty U.S. Air Force personnel numbers also decreased between 1995 and 2015, although has started to increase slightly since 2015. The number decreased again in 2021, when the Air Force had ******* personnel.

As of May 2025, China had the largest armed forces in the world by active duty military personnel, with about two million active soldiers. India, the United States, North Korea, and Russia rounded out the top five largest armies. Difference between active and reserve personnel Active personnel, also known as active duty in the United States and active service in the United Kingdom, are those individuals whose full-time occupation is being part of a military force. Active duty contrasts with a military’s reserve force, which are individuals who have both a military role and a civilian career. The number of active duty forces in the U.S. is much larger than its reserve membership. What is the strongest army? The strength of a country’s armed forces is not only determined by how many personnel they maintain, but also the number and quality of their military equipment. For example, looking only at personnel does not factor in the overwhelmingly higher number of nuclear warheads owned by Russia and the United States compared to other countries. One way to answer this question is to look at the total amount of money each country spends on their military, as spending includes both personnel and technology. In terms of countries with the highest military spending, the United States leads the world with an annual budget almost three times larger than second-placed China.

Armed forces personnel, total in World was reported at 27406000 in 2020, according to the World Bank collection of development indicators, compiled from officially recognized sources. World - Armed forces personnel, total - actual values, historical data, forecasts and projections were sourced from the World Bank on July of 2025.

Thailand military size for 2020 was 455,000, a 0% increase from 2019.

<ul style='margin-top:20px;'>

<li>Thailand military size for 2019 was <strong>455,000</strong>, a <strong>0.03% increase</strong> from 2018.</li>
<li>Thailand military size for 2018 was <strong>454,850</strong>, a <strong>0.03% decline</strong> from 2017.</li>
<li>Thailand military size for 2017 was <strong>455,000</strong>, a <strong>0.1% increase</strong> from 2016.</li>
</ul>Armed forces personnel are active duty military personnel, including paramilitary forces if the training, organization, equipment, and control suggest they may be used to support or replace regular military forces.

Bangladesh BD: Armed Forces Personnel: Total data was reported at 227,000.000 Person in 2020. This stayed constant from the previous number of 227,000.000 Person for 2019. Bangladesh BD: Armed Forces Personnel: Total data is updated yearly, averaging 214,000.000 Person from Jun 1985 (Median) to 2020, with 33 observations. The data reached an all-time high of 252,000.000 Person in 2005 and a record low of 91,300.000 Person in 1985. Bangladesh BD: Armed Forces Personnel: Total data remains active status in CEIC and is reported by World Bank. The data is categorized under Global Database’s Bangladesh – Table BD.World Bank.WDI: Defense and Official Development Assistance. Armed forces personnel are active duty military personnel, including paramilitary forces if the training, organization, equipment, and control suggest they may be used to support or replace regular military forces.;International Institute for Strategic Studies, The Military Balance.;Sum;Data for some countries are based on partial or uncertain data or rough estimates.

Ukraine UA: Armed Forces Personnel: % of Total Labour Force data was reported at 1.406 % in 2016. This records an increase from the previous number of 1.223 % for 2015. Ukraine UA: Armed Forces Personnel: % of Total Labour Force data is updated yearly, averaging 1.406 % from Dec 1992 (Median) to 2016, with 25 observations. The data reached an all-time high of 2.101 % in 1995 and a record low of 0.563 % in 2013. Ukraine UA: Armed Forces Personnel: % of Total Labour Force data remains active status in CEIC and is reported by World Bank. The data is categorized under Global Database’s Ukraine – Table UA.World Bank.WDI: Defense and Official Development Assistance. Armed forces personnel are active duty military personnel, including paramilitary forces if the training, organization, equipment, and control suggest they may be used to support or replace regular military forces. Labor force comprises all people who meet the International Labour Organization's definition of the economically active population.; ; International Institute for Strategic Studies, The Military Balance.; Weighted average; Data for some countries are based on partial or uncertain data or rough estimates.

In 2025, the United States had the largest number of active military personnel out of all North Atlantic Treaty Organization (NATO) countries, with almost *** million troops. The country with the second-largest number of military personnel was Türkiye, at around ******* active personnel. Additionally, the U.S. has by far the most armored vehicles in NATO, as well as the largest Navy and Air Force. NATO in brief NATO, which was formed in 1949, is the most powerful military alliance in the world. At its formation, NATO began with 12 member countries, which by 2024 had increased to 32. NATO was originally formed to deter Soviet expansion into Europe, with member countries expected to come to each other’s defense in case of an attack. Member countries are also obliged to commit to spending two percent of their respective GDPs on defense, although many states have recently fallen far short of this target. NATO in the contemporary world Some questioned the purpose of NATO after the fall of the Berlin Wall in 1989 and the collapse of the Soviet Union a few years later. In 2019, French President Emmanuel Macron even called the organization 'brain-dead' amid dissatisfaction with the leadership of the U.S. President at the time, Donald Trump. NATO has, however, seen a revival after Russia's invasion of Ukraine in February 2022. Following the invasion, Sweden and Finland both abandoned decades of military neutrality and applied to join the alliance, with Finland joining in 2023 and Sweden in 2024.

Estonia military size for 2020 was 7,000, a 0% increase from 2019.

<ul style='margin-top:20px;'>

<li>Estonia military size for 2019 was <strong>7,000</strong>, a <strong>4.48% increase</strong> from 2018.</li>
<li>Estonia military size for 2018 was <strong>6,700</strong>, a <strong>11.67% increase</strong> from 2017.</li>
<li>Estonia military size for 2017 was <strong>6,000</strong>, a <strong>6.25% decline</strong> from 2016.</li>
</ul>Armed forces personnel are active duty military personnel, including paramilitary forces if the training, organization, equipment, and control suggest they may be used to support or replace regular military forces.

Mexico military size for 2020 was 341,000, a 3.96% increase from 2019.

<ul style='margin-top:20px;'>

<li>Mexico military size for 2019 was <strong>328,000</strong>, a <strong>5.75% decline</strong> from 2018.</li>
<li>Mexico military size for 2018 was <strong>348,000</strong>, a <strong>3.57% increase</strong> from 2017.</li>
<li>Mexico military size for 2017 was <strong>336,000</strong>, a <strong>0.01% decline</strong> from 2016.</li>
</ul>Armed forces personnel are active duty military personnel, including paramilitary forces if the training, organization, equipment, and control suggest they may be used to support or replace regular military forces.

Armed forces personnel of Australia increased by 1.69% from 59,000 number in 2019 to 60,000 number in 2020. Armed forces personnel are active duty military personnel, including paramilitary forces if the training, organization, equipment, and control suggest they may be used to support or replace regular military forces.

Armed forces personnel of Singapore remained stable at 59,000 number over the last 2 years. Armed forces personnel are active duty military personnel, including paramilitary forces if the training, organization, equipment, and control suggest they may be used to support or replace regular military forces.

Romania RO: Armed Forces Personnel: Total data was reported at 149,200.000 Person in 2016. This records a decrease from the previous number of 150,400.000 Person for 2015. Romania RO: Armed Forces Personnel: Total data is updated yearly, averaging 177,000.000 Person from Dec 1985 (Median) to 2016, with 29 observations. The data reached an all-time high of 307,500.000 Person in 1996 and a record low of 126,000.000 Person in 1990. Romania RO: Armed Forces Personnel: Total data remains active status in CEIC and is reported by World Bank. The data is categorized under Global Database’s Romania – Table RO.World Bank.WDI: Defense and Official Development Assistance. Armed forces personnel are active duty military personnel, including paramilitary forces if the training, organization, equipment, and control suggest they may be used to support or replace regular military forces.; ; International Institute for Strategic Studies, The Military Balance.; Sum; Data for some countries are based on partial or uncertain data or rough estimates.

Armed forces personnel of Iran remained stable at 650,000 number over the last 2 years. Armed forces personnel are active duty military personnel, including paramilitary forces if the training, organization, equipment, and control suggest they may be used to support or replace regular military forces.

Armed forces personnel of Guatemala remained stable at 43,000 number over the last 1 years. Armed forces personnel are active duty military personnel, including paramilitary forces if the training, organization, equipment, and control suggest they may be used to support or replace regular military forces.