The History of the Odometer

How Far Have You Driven?

An odometer records the distance that a vehicle travels. In this way, it is different from a speedometer that measures the vehicle's speed or the tachometer that indicates the speed of rotation of the engine, although you may see all three on the dashboard of an automobile.


Encyclopedia Britannia credits Roman architect and engineer Vitruvius with inventing an odometer around 15 BC. This used a chariot wheel, which is of standard size and turned 400 times in a Roman mile.

It was mounted in a frame with a 400-tooth cogwheel and for each mile, the cogwheel engaged a gear that dropped a pebble into the box. You knew how many miles you went by counting the pebbles. It was pushed by hand. It may never have been actually built and used

Chang Heng

Chang Heng, the inventor of the known seismograph, also invented an odometer that had a figure that struck a drum as each li or 0.5 km went by to measure distance.

Blaise Pascal

Blaise Pascal (1623 - 1662) invented a prototype of an odometer, a calculating machine called a pascaline. The pasacaline was constructed of gears and wheels. Each gear contained 10 teeth that when moved one complete revolution, advanced a second gear one place. This is the same principal employed in the mechanical odometer.

Thomas Savery - Odometer Used on Ships

Thomas Savery (1650 - 1715) was an English military engineer and inventor who in 1698, patented the first crude steam engine, among Savery's other inventions was an odometer for ships, a device that measured distance traveled.

Ben Franklin - Odometer Used to Measure Postal Routes

Ben Franklin (1706-1790) is best known as a statesman and writer. However, he was also an inventor who invented swim fins, bifocals, a glass armonica, watertight bulkheads for ships, the lightning rod, a wood stove, and an odometer. While serving as Postmaster General in 1775, Franklin decided to analyze the best routes for delivering the mail.

He invented a simple odometer to help measure the mileage of the routes that he attached to his carriage.

William Clayton, Orson Pratt, Appleton Milo Harmon - Odometer called the Roadometer

An odometer called the roadometer was invented in 1847 by the Morman pioneers crossing the plains from Missouri to Utah. The roadometer attached to a wagon wheel and counted the revolutions of the wheel as the wagon traveled. It was designed by William Clayton and Orson Pratt and built by carpenter Appleton Milo Harmon.

William Clayton was inspired to invent the roadometer by his first method of recording the distance the pioneers traveled each day. Clayton had determined that 360 revolutions of a wagon wheel made a mile, he then tied a red rag to the wheel and counted the revolutions to keep an accurate record of the mileage traveled. After seven days, this method became tiresome, and Clayton went on to invent the roadometer, first used on the morning of May 12, 1847. William Clayton is also known for his writing of the pioneer hymn "Come, Come, Ye Saints."

"I walked some this afternoon in company with Orson Pratt and suggested to him the idea of fixing a set of wooden cog wheels to the hub of a wagon wheel, in such order as to tell the exact number of miles we travel each day.​​ 

"About noon today Brother Appleton Harmon completed the machinery on the wagon called a 'roadometer' by adding a wheel to revolve once in ten miles, showing each mile and also each quarter mile we travel, and then casing the whole over so as to secure it from the weather." ~ From William Clayton's Journal

Samuel McKeen - Odometer used on Carriage

In 1854, Samuel McKeen of Nova Scotia designed an early version of the odometer, a device that measures mileage driven. His was attached to the side of a carriage and measured the miles with the turning of the wheels.