Interactive Split Tool

Co-Parent Expense Split Calculator

Calculate exact reimbursement amounts for medical co-pays, school fees, and childcare using 50/50, 60/40, or custom income-based split ratios.

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You — 50%Co-parent — 50%

Enter both incomes to calculate a proportional split — defaults to 50/50 until you do.

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Your share
$0.00
Co-parent's share
$0.00

How to Calculate a 50/50 Expense Split

In an equal 50/50 split, each parent pays half of the total expense amount. If Parent A pays a $240 medical bill up front, Parent B's reimbursement share is calculated as:

$240 ÷ 2 = $120 reimbursement owed to Parent A

How to Calculate a 60/40 Expense Split

In a proportional 60/40 income split, the higher-earning parent pays 60% of the cost and the lower-earning parent pays 40%. For a $240 extracurricular fee paid by Parent B (40% share parent):

Parent A share (60%): $240 × 0.60 = $144 reimbursement owed to Parent B
Parent B share (40%): $240 × 0.40 = $96 (retained share)

Featured Snippet: What is a 60/40 split of $500?

A 60/40 split of $500 is $300 (60% share) and $200 (40% share). To calculate, multiply $500 by 0.60 for the 60% share and by 0.40 for the 40% share.

→ Read our complete 60/40 vs 50/50 Expense Split Guide→ Learn how to track shared child expenses
FAQ

Questions about child expense calculations.

What is a fair way to split child expenses between co-parents?

Co-parents often split costs equally (50/50) or proportionally according to relative gross monthly incomes (e.g. 60/40 or 70/30) based on parenting plans or court decrees.

Is a 50/50 expense split legally required?

No. Expense split percentages are determined by your court decree, divorce settlement, or mutual parenting agreement. Always follow your legal orders.

Is this calculator legally binding?

No. This calculator is an educational calculation tool. For formal legal advice, consult your family law attorney.

Last updated: August 8, 2026 · fairsplit.live/calculator