Australian family law doesn't begin with a formula. It begins with a question: what arrangement is in the best interests of this child? That is the paramount consideration under the Family Law Act 1975 (Cth), and everything else - including how much time each parent gets - flows from it.

When the Federal Circuit and Family Court of Australia decides a parenting case, section 60CC of the Act directs it to consider:

• the safety of the child and of each person who has care of the child, including any history of family violence and any family violence order;
• any views expressed by the child, given weight according to their age and maturity;
• the child's developmental, psychological, emotional and cultural needs;
• the capacity of each person who has or is proposed to have parental responsibility to meet those needs;
• the benefit to the child of a relationship with each parent and other significant people, where it is safe; and
• anything else relevant to the particular child.

Nowhere in that list is a presumption that time will be split equally.

For a period, the legislation contained a presumption of "equal shared parental responsibility" - which was about decision-making, not time - and a requirement to consider equal time where that presumption applied. That framework was widely misunderstood as an entitlement to 50/50. It was removed by the Family Law Amendment Act 2023, which commenced on 6 May 2024. Today the law is simpler and blunter: best interests, assessed on the evidence, child by child.

Two things follow from the absence of a 50/50 starting point.

First, don't anchor your expectations (or your position in mediation) to a fraction. Proposals framed around your child's actual week - school, sport, sleep, transitions - are more persuasive to the other side, to mediators, and ultimately to a court than proposals framed around percentages.

Second, evidence matters more than assertion. The parent who can show a track record of meeting the children's needs, supporting their relationship with the other parent, and behaving sensibly under pressure is in a far stronger position than the parent with a spreadsheet of nights. A related tip we give every client: assume every text message you send your former partner will one day be read by a judge. Write accordingly.

There is no automatic anything. The law asks what is in your child's best interests, and answers it on evidence. Build your proposal around your child's real life, keep your conduct exemplary, and get advice early - the first weeks after separation shape the arrangements more than most people realise.

Source: Family Law Act 1975 (Cth) (Compilation No. 101, compiled 10 June 2025; the latest compilation on the Federal Register of Legislation as at 4 November 2026), ss 60CA and 60CC; Federal Circuit and Family Court of Australia. The law changes from time to time, so please get advice about your own matter before relying on this general information.