Enter the number of days the child spends with each parent per year into the calculator to determine the custody percentage for Parent 1. The custody percentage for Parent 2 can be calculated by subtracting Parent 1’s percentage from 100%.

Custody Percentage Formula

The following formula is used to calculate the custody percentage for Parent 1:

CP1 = (DP1 / (DP1 + DP2)) * 100

Variables:

  • CP1 is the custody percentage for Parent 1 (%)
  • DP1 is the number of days the child spends with Parent 1 (per year)
  • DP2 is the number of days the child spends with Parent 2 (per year)

To calculate the custody percentage for Parent 1, divide the number of days the child spends with Parent 1 by the total number of days spent with both parents and then multiply by 100 to get the percentage. The custody percentage for Parent 2 is simply 100% minus the custody percentage for Parent 1.

What is Custody Percentage?

Custody percentage represents the proportion of time a child spends with each parent, usually over the course of a year. This is often used in family law to determine child support obligations, visitation rights, and other legal matters related to child custody arrangements. It is an important metric that reflects the division of parenting time and responsibilities.

How to Calculate Custody Percentage?

The following steps outline how to calculate the Custody Percentage for Parent 1.


  1. First, determine the number of days the child spends with Parent 1 (DP1) per year.
  2. Next, determine the number of days the child spends with Parent 2 (DP2) per year.
  3. Use the formula CP1 = (DP1 / (DP1 + DP2)) * 100 to calculate the custody percentage for Parent 1.
  4. Finally, calculate the custody percentage for Parent 2 by subtracting Parent 1’s percentage from 100%.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Days with Parent 1 (DP1) = 200 days per year

Days with Parent 2 (DP2) = 165 days per year