Compute tractor speed. The standard equation for speed is distance divided by time. For example, given a standard tractor travelling on a level field for a distance of 100 feet, for a period of 45 seconds, speed is computed as (100/45) which equals 2.2 feet per second. Recognize that tractor speeds will vary depending on vendor, type and model. Any distinguishing feature can influence the ability and speed of current tractors.
Consult the owner's manual. Speed can vary across vendors and within a specific line of one vendor's stock. For example, a Troybilt lawn tractor's ground speed ranges from zero to six mph across the 11 models in the lawn-care line of products, compared to speeds of zero to nine mph across the seven models in their garden-tractor line of products.
Understand that these published speeds are based on the specifications of a new and properly tuned tractor, so any component wear, improper adjustments or external or internal anomalies can influence stated performance, as noted in the Troybilt manual but generally applicable to all machines.