The amount of coins you earn in a game is determined by the normal amount of coins you would earn multiplied by your current coin multiplier.
You can increase your multiplier by using a network booster, a private booster, or through special events which would allow you to gain a lot more coins then you usually would.
In order to find out your coin multiplier, you will need to include the following factors:
Your base multiplier: If you are just starting out on Hypixel, this is 1.0x. As you level up, this can go up to 8.0x. You can see your current base multiplier in the leveling menu on your ingame profile. To learn more about leveling, view Hypixel Network Leveling and Experience.
Private Boosters: These can give yourself a certain multiplier for a limited time. For example, there is a 4.0x private booster that you can get from the delivery man. To see your boosters, type /booster in a lobby.
Game Multipliers: Each game has its own multiplier depending on active Network Boosters and Events. You can see this by hovering over a game in the compass.
To find out your multiplier, you have to add your base multiplier, private boosters, and game multipliers together - do not multiply them!
You are level 50, which gives you 5.0x coins, the game you are playing has 3.0x coins and you are using a personal booster that gives you 2.0x coins.
5.0 + 3.0 + 2.0 = 10.0. You will receive 10x the normal amount of coins.
If a game gives you 5 coins per kill, you would instead get 50.
Getting boosters is a great way to support the server and increase your coin multiplier.
You can buy Network Boosters on the Hypixel Server Store.
Private Boosters are only available through special events, leveling rewards, or through the Delivery Man.