This is an interesting video on Youtube about USA vs Iran: Military Units Power Comparison 2020. There are many interesting pictures of military vehicles and aircraft here. For most of these units, USA has greater number than Iran. You can see interesting Army Airforce and Navy of both countries.
USA Active Personnel: 1,286,000
Iran Active Personnel: 550,000
For some units (such as Towed Artillery and Navy Patrol Vessels), Iran actually has more than USA, according to this video.
The United States Armed Forces are the military forces of the USA. It consists of the Army, Marine Corps, Navy, Air Force, Space Force and Coast Guard.
The Iranian Armed Forces comprise the Army, the Revolutionary Guard Corps and the Law Enforcement Force of the Islamic Republic of Iran. All branches of armed forces fall under the command of General Staff of Armed Forces.
This is where the information comes from: