What does a child's plane ticket actually cost? We checked - across 37 airlines.

Book a flight for one adult and the price is the price. Add a child and an infant, and suddenly the total on your screen is doing quiet arithmetic you can't see. Is the child half price? Is the baby free? Why did the total jump more than you expected?

Airlines almost never show you the per-person maths, they quote one combined figure for the whole party. So we decided to work it out ourselves. We ran controlled price checks across ten routes from London to Delhi, Islamabad, Rome, Malaga, Dublin, New York, Jeddah and more comparing the same flight priced for an adult alone, then with a child, then with an infant. Thirty-seven airlines later, clear patterns emerged.

What we found

Flying long-haul? Children typically cost about three-quarters of the adult fare. Across the long-haul carriers we tested — Emirates, Qatar Airways, Etihad, Turkish, Singapore Airlines, Saudia and others, a child seat came out between 69% and 84% of the adult price, clustering around 77%.

Crossing the Atlantic? The discount is almost uniform. British Airways, Virgin Atlantic, American, Delta and JetBlue all priced a child at almost exactly 74% of the adult fare on London–New York. Rare agreement in an industry famous for disagreeing.

Flying short-haul in Europe? The child discount largely disappears. On routes like Gatwick to Malaga and Heathrow to Dublin, most airlines including the big legacy names charge children 93 - 100% of the adult fare. Low-cost carriers almost always charge full price for a child. The honourable exception: Jet2, which still offered a genuine child discount (around 28% off) in our checks. easyJet sat in between.

Infants on a lap are cheap - but not always that cheap. A lap infant typically added 9-20% of the adult fare on long-haul flights, but on short-haul the flat infant fees can amount to 25-40% of a low base fare. A "£25 baby fee" feels different on a £700 ticket than on a £70 one.

One more thing we confirmed: an infant under two travels on a lap. If you want your under-two in their own seat, that generally has to be arranged with the airline directly it isn't something most booking systems can price upfront. Once they turn two, they're a child fare with their own seat automatically.

Why you'll care at the checkout

None of this is visible when you book — anywhere. Every travel site, ours included, receives one total price for your party from the airline's systems. The per-person split simply isn't provided.

That bothered us, because families budget per person. So we built something.

The new Price Guide on Cypher Travel

Search flights on Cypher Travel with children or infants in your party and you'll now see a small ⓘ next to the price on every result. Tap it and you'll get an indicative per-traveller breakdown — adults, children, infants that always adds up to the exact price shown, based on the real pricing patterns we measured for that airline (or typical patterns for its route type where we haven't measured it yet).

It's clearly labelled for what it is: an indicative guide, not a quote the airline sets the final per-traveller fare at booking. But it turns one opaque number into something a family can actually reason about: roughly this much for us, this much for the kids, this much for the baby.

It's a small thing. It's also exactly the kind of thing we think travel booking should have done years ago.

Complex travel, made easy - that's the point of Cypher Travel.

Prices and percentages from checks carried out in August 2026 on economy fares. Patterns are indicative and vary by airline, route, season and fare type.