I answered a similar question to this some time ago here but I'll repost it below.
American soldiers were quite well-paid in comparison to civilians. The United States Army (including the Army Air Forces), Navy, and the Marine Corps all utilized the same pay scale in WWII.
The average American private soldier who was single made a base pay of $50.00 ($30.00 prior to September 1942) per month, or $600.00 before any spending per year. Accounting for the soldier being in the military, (and not having to pay taxes if their yearly income was under $1,500.00, or buy luxury or necessity items that were provided by the military such as food, clothes or soap) that would scale out to a net annual pay of about $3,600.00 "civilian" dollars in 1944. In 1944, an annual income of $3,600.00 was more than 80 percent of all single workers in the United States.
For the below chart I've used US Army, Navy, and Marine Corps ranks as an example, and copied the pay scales up to six or nine years. The Marines split their ranks up into a bewildering array of sub-designations at each pay grade just like the Navy; as there's less than the Navy, I chose to list them.
On September 22, 1942, in Change 3 of AR 600-35, the rank of First Sergeant was moved from Grade 2 to Grade 1; this chart reflects that change
WWII US monthly base pay at each rank to six or nine years, effective from June 1, 1942 to June 30, 1946:
| Pay Grade (for enlisted men)/Pay Period (for officers) | Army | Navy | Marine Corps | Under 3 years' service | After 3 years | After 6 years | After 9 years |
|---|---|---|---|---|---|---|---|
| 7 | Private | Apprentice Seaman | Private | $50.00 | $52.50 | $55.00 | |
| 6 | Private First Class | Unrated Man, Second Class | Private First Class/Field Musician 1st Class/Steward's Ass't. 2nd Class | $54.00 | $56.70 | $59.40 | |
| 5 | Corporal/Technician 5th Grade | Unrated Man, First Class | Corporal/Ass't. Cook/Field Musician Corporal | $66.00 | $69.30 | $72.60 | |
| 4 | Sergeant/Technician 4th Grade | Petty Officer, Third Class | Sergeant/Field Musician Sgt./Field Cook/Steward 3rd Class/Cook 3rd Class | $78.00 | $81.90 | $85.80 | |
| 3 | Staff Sergeant/Technician 3rd Grade | Petty Officer, Second Class | Staff Sgt./Platoon Sgt./Chief Cook/Steward 2nd Class/Cook 2nd Class | $96.00 | $100.80 | $105.60 | |
| 2 | Technical Sergeant | Petty Officer, First Class | Technical Sergeant/Gunnery Sgt./Drum Major/Technical Sgt./Supply Sgt./Steward 1st Class/Cook 1st Class | $114.00 | $119.70 | $131.10 | |
| 1 | Master Sergeant/First Sergeant | Chief Petty Officer | Sergeant Major/Master Gunnery Sgt./Master Sgt./First Sgt./Master Technical Sgt./Quartermaster Sgt./Paymaster Sgt./Master Steward/Master Cook | $138.00 | $144.90 | $151.80 | |
| 1 | Second Lieutenant | Ensign | Second Lieutenant | $150.00 | $157.50 | $183.33 | $191.67 |
| 2 | First Lieutenant | Lieutenant (junior grade) | First Lieutenant | $166.67 | $175.00 | $183.33 | $230.00 |
| 3 | Captain | Lieutenant | Captain | $200.00 | $210.00 | $220.00 | |
| 4 | Major | Lieutenant Commander | Major | $250.00 | $262.50 | $275.00 | |
| 5 | Lieutenant Colonel | Commander | Lieutenant Colonel | $291.67 | $306.25 | $320.83 | |
| 6 | Colonel | Captain | Colonel | $333.33 | $350.00 | $366.67 | |
| 7 | Brigadier General | Commodore | Brigadier General | $500.00 | same | same | |
| 8 | Major General | Rear Admiral | Major General | $666.67 | same | same | |
| 8 | Lieutenant General | Vice Admiral | Lieutenant General | $666.67 | same | same | |
| 8 | General | Admiral | General | $666.67 | same | same | |
| 9 | General of the Army | Admiral of the Navy | -- | $1,125.00 | same | same |
The various types of warrant officers had their own unique pay scale; see my first link
Women in the military were awarded the same pay as men
For each three years in service, up to a maximum of thirty years, a soldier's base pay was increased five percent based upon the amount of previous pay. For example, a private who had a base pay of $50.00 per month for his first three years would then earn $52.50 per month during his 3rd to 6th years, and $55.00 during his 6th to 9th years in service. This percentage was calculated and instituted with the passage of Public Law 77-607, known as the "Pay Readjustment Act of 1942."
For several officer ranks' three-year service periods (like above), the pay, along with that of a rank above or below, is boosted to end up matching. To effect the "match," a pay increase of more than 5 percent happens in that period. The next 3-year period pay increase is also then more than 5 percent. After that, the scale returns to normal with the rank above making more. This seems to be a function of time in service. See my fourth link for an overview of the whole pay chart where you can see the matches and how they "progressed" through the chart.
Soldiers holding any of the five general officer ranks received a base pay and did not experience this five-percent increase, no matter how many years they served.
If an officer stayed at a rank for a set amount of time, (5 years for 2nd lieutenants or equivalent, 10 years for 1st lieutenants or equivalent, 17 years for captains or equivalent, 23 years for majors or equivalent, and 30 years for lieutenant colonels or equivalent) he was then entitled to the pay of the next-highest officer rank.
If a soldier had dependents, such as children, a wife, brothers or sisters, or parents he needed to support, he would receive additional pay; see my third link for the complicated chart. For service overseas, including in Alaska, base pay at each rank was increased 20 percent.
If a soldier was awarded the Medal of Honor, the Distinguished Service Cross, the Distinguished Service Medal, or the Soldier's Medal, he would earn an extra $2.00 per month. Each additional award of the above medals netted another $2.00 bonus per month.
Air Corps men who were qualified to fly or took regular flights received an additional pay per month amounting to 50 percent of their base pay. Enlisted paratroopers or paratroopers-in-training received an additional pay of $50.00 per month, no matter their base pay; officers received $100.00. This is what you were alluding to. Glider troops initially did not receive the $50.00 or $100.00 hazard pay. After various assaults proved that landing via glider was just as dangerous, if not more dangerous, than parachuting, a hazard pay of $25.00 per month for enlisted glider troops and $50.00 for officers was instituted.
Sources:
- Army-Navy Pay Tops Most Civilians'; Unmarried Private's Income Equivalent to $3,600 Salary, (Barron's National Business and Financial Weekly, April 24, 1944) by Malvern Hall Tillitt
- Pay of the WW2 Enlisted Man (per WAC Life, (War Department Pamphlet 35-3) April 30, 1945)