Our Family Lizard

Custody Time Percentage Calculator

Free · no account · the math runs in your browser and nothing you type leaves it

Your custody percentage is the share of time the kids are actually in your care — counted in hours, not just overnights. The schedule on paper and the schedule you're living are rarely the same document. This page does the quick math; the full app tracks the real hours month by month.

50%
Your time
50%
Other parent
4,380
Your hours / year

How the math works

A repeating 2-week cycle contains 336 hours. Count the hours the children are in your care across one full cycle — including school pickups, practices, and dinners, not just nights — and divide by 336. Multiply by 8,760 (hours in a year) for the annual figure.

Common schedules and their real percentages

ScheduleHours per 2-week cycleYour time
Week on / week off16850%
2-2-3 rotation16850%
2-2-5-5 rotation16850%
60/40 (4-3 split)20260%
Extended every-other-weekend (Thu 6pm–Mon 8am) + weekly midweek overnight11434%
Every other weekend (Fri 6pm–Sun 6pm) + weekly 3-hour dinner5416%
Every other weekend only4814%

Hours vs. overnights — why the difference matters

Many state child-support formulas count overnights. But overnights ignore the caregiving that fills a week: the 7am school runs, the soccer practices, the homework dinners. A parent with "every other weekend plus a weeknight dinner" has 14% of the overnights but does far more than 14% of the driving. Knowing both numbers is the point — the overnight count drives the formula, the hours count describes your actual life, and the gap between them is what you bring to the negotiation.

What the percentage gets used for Child-support calculations, proposals and counter-proposals, and the "we split everything 50/50" conversation. When your ex's proposal says 50/50 and the lived schedule computes to 58/42, the percentage is your receipt.

This page is the quick math. The app is the receipts.

Our Family Lizard tracks your actual custody hours month by month, logs the driving burden, computes support and take-home pay per household, and projects it all until the youngest turns 18 — with side-by-side comparison of their offer vs. your counter. Free for the basics. No account. Everything stays in your browser.

Run your real numbers →

This is a calculator with opinions, not legal advice. Support formulas and how custody time is counted vary by state and country — confirm with a professional for anything you sign. Built by a divorcing dad of four who got tired of paying $350/hr for math.