Gear Ratio Speed Calculator

Mechanical gear systems operate on the principle of proportional movement based on tooth count. The fundamental equations governing gear speed are: 1) Gear Ratio = Output Teeth / Input Teeth. 2) Output Speed = Input Speed / Gear Ratio. 3) Gear Ratio Inverse = 1 / Gear Ratio. When a smaller gear drives a larger gear, the output speed decreases while torque increases. Conversely, a larger driving gear increases the rotational speed of the smaller output gear while reducing torque.

Imagine you are designing a mechanical transmission system where an input driving gear has 15 teeth and spins at an input speed of 1,200 RPM. It drives a larger output gear featuring 45 teeth. First, calculate the gear ratio: Gear Ratio = 45 / 15 = 3. This means the system has a 3:1 reduction ratio. Next, compute the output speed: Output Speed = 1,200 RPM / 3 = 400 RPM. Thus, the output gear rotates at 400 RPM with triple the torque of the input gear.

Always double-check your tooth counts, as even a single-tooth discrepancy alters your final output speed ratio. Remember that idler gears placed between the driver and driven gears affect the rotational direction but do not alter the overall speed ratio calculation. When designing high-speed transmissions, ensure material strength and lubrication tolerances match your calculated output velocities to prevent premature mechanical wear.