Race weekends · Updated for 2026
F1 out-laps and in-laps explained
The preparation and return laps surrounding a timed run or pit stop.
Quick answer
An out-lap begins when a car leaves the pits and is used to prepare tyres, brakes and energy for a timed lap. An in-lap ends with pit entry and may be used to cool or conserve the car.
Building the window
Drivers use braking, acceleration and cornering load to bring tyres and brakes toward their target temperatures before the lap that counts.
Creating a gap
The engineer helps place the car in clear air. Going too slowly can breach session rules or obstruct another driver, while going too quickly can catch traffic.
The in-lap
After a run, the driver may cool brakes, harvest energy and assess the tyres before returning to the box. In a race, a fast in-lap before a stop can decide an undercut.