Each Force collects the gold they earn until the 5 minute mark. The gold will then be distributed between every player of the Force, based on this formula:

ForceGold * 4 / (<number of players in a team> * 9 + 15)

When working with real numbers, it comes down to this:

• 5 players = 33.33% (6.67% for each player)
• 4 players = 31.37% (7.84% for each player)
• 3 players = 28.57% (9.52% for each player)
• 2 players = 24.24% (12.12% for each player)
• 1 player = 16.66%

As you can see, when there are less players in one team, each of them receives more gold, but the team as a whole, gets less money. The gold which wasn’t distributed between the players is lost and the Force’s gold is set to 0.
The Force normally also upgrades the troops, when all upgrades already have been researched, the gold for the upgrades will also be added to Force’s gold, before the distribution.

When destroying a Factory of the enemy base, your Force receives a compensation for the lost creep gold. For each creep, which isn’t spawning, because it’s factory has been destroyed, your Force receives 4 times the bounty of this creep. The same happens with captured Control Points.
Note: Player build Factories have no influence on this.

Example: The game lasted already one hour and your team of 5 players holds every CP
After one hour, one Marine is worth 24 gold, since two Marines spawn at each CP, there is a total of 12 Marines, which is a total of 288 gold. So your Force receives 1152 gold (4 x 288 gold) every 20 seconds for your Control Points. After 5 minutes (they spawn 3 times a minute = 15 spawns), that’s a total of 17280 gold. So each player will get about 1153 gold, just for the owned Control Points.

Additionally, each player also gets income each second, it calculated that way:

32 / (<number of players in a team> * 3 +5)

100% Efficiency = 8 distributed every second to players

• 5 players = 1.6 gold every second for each player (100%)
• 4 players ~ 1.88 gold every second for each player (~94%)
• 3 players ~ 2.28 gold every second for each player (~85.6%)
• 2 players ~ 2.90 gold every second for each player (~72.7%)
• 1 player = 4 gold every second for each player (50%)