Timeshare and Child Support in California
California builds the timeshare into the child support formula through H%, the approximate share of time the higher earner has the children. Support falls as the higher earner’s time rises toward half and can reverse beyond it, and a higher earner can still pay at an equal timeshare.
How H% enters the formula
H% is the approximate percentage of time the higher earner has or will have primary physical responsibility for the children compared to the other parent. It appears twice in CS = K[HN − (H%)(TN)]: inside K, which is one plus H% (when H% is 50% or less) or two minus H% (when it is greater), and in the term (H%)(TN), which subtracts the share of total income that matches the higher earner’s time. If the arrangements differ among the children, H% is the average of the percentages for each child (Section 4055(b)(1)(D)).
What happens as the timeshare changes
In this example, two children, the higher earner has net income of $6,000 and the other parent $3,000. The table shows the guideline amount at different shares of time with you (the higher earner):
| Your share of the time | Guideline support |
|---|---|
| 0% | You pay $2,400 |
| 10% | You pay $2,244 |
| 20% | You pay $2,016 |
| 30% | You pay $1,716 |
| 40% | You pay $1,344 |
| 50% | You pay $900 |
| 60% | You pay $336 |
| 70% | Other parent pays $156 |
| 80% | Other parent pays $576 |
| 90% | Other parent pays $924 |
| 100% | Other parent pays $1,200 |
Support falls as your time rises, reaches its lowest paid amount near half time, and then reverses: once you have the children most of the time, the other parent, who has less income, pays you.
Equal time does not mean no support
At a 50% timeshare the term HN − (H%)(TN) equals half the difference between the two incomes, so a higher earner still pays when time is equal and incomes are not. In the example the higher earner would pay $900 a month at 50% even though the children spend half the time with each parent.
Defaults and missing evidence
In a default proceeding where proof is by affidavit, or when a party fails to appear after notice, H% is set at zero if the noncustodial parent is the higher earner or at 100 if the custodial parent is the higher earner, where there is no evidence of the noncustodial parent’s time (Section 4055(b)(6)). A statement by the party who is not in default about the percentage of time is sufficient evidence.
A parent not using the time
The statute uses the time a parent has or will have with the children. Because the formula depends on it, a significant change in the actual timeshare can support a request to revisit support; see the California child support calculator for the guideline amount at the new timeshare.
Questions to bring to an attorney
Ask how the timeshare in your parenting plan will be counted, whether your actual schedule differs from the written one, how a change in the schedule would change the formula result, and whether the low-income adjustment or any rebuttal factor in Section 4057(b) could apply to your income.
Where this fits
How the full formula works, including K and the multiplier for more children, is in how the California formula works.
Frequently asked questions
What is H% in California child support?
The approximate percentage of time the higher earner has or will have primary physical responsibility for the children compared to the other parent.
Does 50/50 custody mean no child support in California?
No. At a 50% timeshare the higher earner can still pay, because the formula subtracts only the share of total income that matches the timeshare.
How does California treat different timeshares for different children?
H% is the average of the approximate percentages of time the higher earner spends with each child.
What is H% in a California default case?
H% is set at zero if the noncustodial parent is the higher earner or 100 if the custodial parent is the higher earner, when there is no evidence of the noncustodial parent's time.
Does more parenting time lower California child support?
For the higher earner, yes: support falls as the higher earner's share of time rises toward and past half, and can reverse so that the lower earner pays.
Official sources
A local family law attorney can review your situation — many offer a free consultation.
This is general information, not legal advice. It is based on the cited California statutes, rules and court opinions, and every case turns on its own facts. Confirm how the law applies to your situation with a licensed California attorney.