How to Use the Infant & Child Airfare Calculator
Flying with kids turns a simple fare lookup into a small math project. Children need their own seat, and infants ride on a parent's lap under fare rules that differ between domestic and international flights. This calculator takes the adult fare, route type, and passenger counts, then works out the total airfare for the whole family in one step.
In general, children (ages 2-11) occupy a full seat, so most U.S. airlines charge the same fare as an adult ticket. Infants under 2 flying as a lap infant typically ride free on domestic flights, while international flights commonly charge around 10% of the adult fare even without a seat, plus taxes. These are common industry practices — actual fares still vary by airline and promotion.
If your infant turns 2 during the trip, the return flight may need to be booked at the child fare instead, so double-check their exact age on each travel date and confirm current fare rules on the airline's website before booking.
Frequently Asked Questions
On U.S. domestic flights, a lap infant under 2 typically flies free since they don't occupy a seat. On international flights, most airlines charge around 10% of the adult fare for a lap infant even without a seat, plus applicable taxes.
Usually not. Children ages 2-11 occupy a full seat, so most U.S. airlines charge the same fare as an adult. A few airlines or routes offer a child discount fare, so it's worth checking before booking.