Identify all sources of income for the month
Add up gross income from salary, wages, freelance work, bonuses, and other earnings
Subtract taxes, insurance, retirement contributions, and other deductions
Use net income if you want take-home monthly income
For weekly income, multiply by 4.33
For biweekly income, multiply by 2.17
For annual income, divide by 12
For hourly income, multiply hourly rate by hours worked per month
Include regular recurring income only if calculating stable monthly income
Exclude one-time or irregular income if you want an average monthly amount