Leonardo da Vinci designed an odometer to record the distance traveled by a vehicle.
His concept used a wheel that turned as the vehicle moved and a counting mechanism that registered the wheel’s rotations. By relating each rotation to the wheel’s circumference, the device could estimate the total distance covered.
Leonardo’s odometer belonged to his broader study of mechanical measurement. It was not an electronic instrument and did not display distance in the digital way modern vehicles do. Instead, it relied on physical motion and counted events mechanically.
The invention is sometimes mixed up with a speedometer. An odometer measures accumulated distance, whereas a speedometer measures speed at a particular moment. Leonardo’s design is therefore best identified as an odometer, even though historical measuring devices often combined several functions.