If a Player is sent off, it is a matter of fact the Player will be suspended 7 days after the date of the game, as set out by The FA in the Discipline Handbook.
The length of ban depends on the type of misconduct:
Serious Foul Play
3 match suspension
5 penalty points
Violent Conduct
3 match suspension
6 penalty points
Spitting at an opponent
6 match suspension
7 penalty points
Denies an obvious goal scoring opportunity by an offence punishable by a free kick or penalty kick
1 match
3 penalty points
Denying an obvious goal scoring opportunity by deliberately handling the ball
1 match
3 penalty points
Use of offensive, or insulting or abusive language
2 matches
4 penalty points
Receiving a second caution in a match
1 match suspension
3 penalty points
You can read more about misconduct charges in the Discipline Handbook which can be found by using the link below:-