Enter the nominal shaft diameter and International Tolerance grade into the calculator to determine the shaft tolerance. This calculator can also evaluate any of the variables given the others are known.

Shaft Tolerance Formula

The following formula is used to calculate the shaft tolerance.

T = (D + IT) - D


  • T is the shaft tolerance (mm) D is the nominal shaft diameter (mm) IT is the International Tolerance grade (mm)

To calculate the shaft tolerance, add the International Tolerance grade to the nominal shaft diameter. Then subtract the nominal shaft diameter from the result. This will give you the shaft tolerance.

What is a Shaft Tolerance?

Shaft tolerance refers to the allowable variation in the dimensions of a shaft, which is a rotating machine element usually used for transmitting power. This variation is specified by engineers to ensure proper function and fit of the shaft within a machine or system. It is crucial for maintaining the performance, efficiency, and longevity of the equipment. The tolerance is typically defined by an upper and lower limit on the shaft’s diameter, and it can be influenced by factors such as manufacturing processes, material properties, and operational conditions.

How to Calculate Shaft Tolerance?

The following steps outline how to calculate the Shaft Tolerance using the given formula:

  1. First, determine the nominal shaft diameter (D) in millimeters.
  2. Next, determine the International Tolerance grade (IT) in millimeters.
  3. Next, substitute the values of D and IT into the formula: T = (D + IT) – D.
  4. Finally, calculate the Shaft Tolerance (T) in millimeters.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge:

nominal shaft diameter (D) = 50 mm

International Tolerance grade (IT) = 0.05 mm