Start with your total income before taxes and deductions
Include your regular salary or wages
Add overtime pay, bonuses, and commissions
Add tips, if applicable
Add self-employment income before expenses
Add rental income before expenses
Add other recurring income sources
Divide annual gross income by 12 if you know your yearly amount
Use the amount shown on your pay stub before deductions if you are paid monthly
Use the total from all income sources for one month to get gross monthly income