Determine how much net income your spouse makes
Remember to include all income, i.e. rentals, royalties, overtime and any other possible money that your spouse makes. Remember to only use net income, which is the income after taxes and dues.
Use the appropriate multiplier
For one child use 20% or .2; for two children 25% or .25; for 3 children 30% or .3 and so forth until the maximum amount of 50% or .5. You have to multiply the net income to the multiplier. Example $2,500 x .2= $500.