Transmission Calculator

The transmission calculator helps you quickly determine vehicle speed, RPM, and the right transmission and differential gear ratios.

Gear ratio13.394091:13.5909 × 3.73 across two stages

TypeReductionslower and stronger at the output

Output speed186.649 rpm3.1108 revolutions a second

Output torque4,410.875 N·m3,253.294 lbf·ft

Torque multiplication12.6025×the ratio less 5.91% lost to friction

Input power91.6298 kW

Output power86.2145 kWpower is what a gearbox cannot increase — only redistribute between torque and speed

Power lost as heat5.4153 kW

Hunting ratio?yes — tooth counts are coprimeevery tooth on one gear eventually meets every tooth on the other, so wear spreads evenly

Revolutions of the driving gear per output turn13.394091

The formula

ratio = driven teeth ÷ driving teeth; torque and speed trade inversely

Torque and speed, never both

A gear ratio is the driven tooth count divided by the driving one. Above one it is a reduction: the output turns more slowly and with proportionally more torque. Below one it is an overdrive, trading torque for speed. Power — torque times angular velocity — is what a gearbox cannot increase; it can only redistribute what it is given, minus a few percent to friction.

The hunting-ratio check is a real design consideration. If the two tooth counts share a common factor, the same pairs of teeth meet over and over, so any manufacturing error or hard spot wears one pair repeatedly. Coprime counts make every tooth eventually meet every other tooth, spreading wear evenly — which is why you often see 15 and 46 rather than 15 and 45.

Multiple stages multiply their ratios and their losses. Two 97% stages give 94% overall, which is why a deep reduction is usually built as a few moderate stages rather than one extreme one.