Calculate Child Support
Before taxes. Include wages, self-employment, bonuses.
California uses the Income Shares — both incomes required.
0 = no custody · 91 = 25% · 182 = 50/50 · 365 = full custody
$0
estimated monthly support payment
⚠️ Estimate only. Actual court-ordered amounts may vary. Verify with a licensed California family law attorney.
ℹ️ California uses the Income Shares — California uses a complex algebraic formula (CS = K[HN-(H%)(TN)]) based on both parents' net disposable income and custody time. Updated by SB 343 in 2024 to use net income calculations.
How Child Support Works in California
California uses the Income Shares to determine child support obligations.
The Income Shares model combines both parents' incomes, finds the basic support obligation from a state schedule, then divides it proportionally. More parenting time (overnights) reduces the non-custodial parent's payment through a parenting time credit.
How California Compares to Other States
See how California's child support rules compare to other states.
| State | Formula | Support Ends | Arrears Rate | Mod. Threshold |
|---|---|---|---|---|
| ★ California (you) | Income Shares | 18 | 10% | 20% |
| Delaware | Melson Formula | 18 | 5% | 10% |
| Idaho | Percentage of Income | 18 | 5% | 15% |
| Michigan | Income Shares | 18 | 5% | 10% |
| Ohio | Income Shares | 18 | 5% | 10% |
| Alaska | Percentage of Income | 18 | 6% | 15% |
| Florida | Income Shares | 18 | 6% | 15% |
| Louisiana | Income Shares | 18 | 6% | 25% |
| New Hampshire | Income Shares | 18 | 6% | 15% |
Showing 8 comparison states. View all 50 states →
Frequently Asked Questions
How is child support calculated in California?
California uses the Income Shares model. California uses a complex algebraic formula (CS = K[HN-(H%)(TN)]) based on both parents' net disposable income and custody time. Updated by SB 343 in 2024 to use net income calculations.
When does child support end in California?
Child support generally ends when the child turns 18 in California.
Can I modify child support in California?
Yes. California requires a 20% or greater change in income to qualify. Use our modification checker →
Does 50/50 custody eliminate child support in California?
Not automatically. The higher-earning parent typically still pays support with 50/50 custody. See our 50/50 guide →
What income is used for child support in California?
Income includes wages, self-employment, bonuses, rental income, unemployment benefits, disability payments, and Social Security. Courts may impute income if a parent is voluntarily underemployed.