If you're looking for a tolerance calculator where you can set your own ± tolerances, you can find it here: Custom Tolerance Calculator 

Instructions

• Measurement Type: Select the type of measurement you're working with - Length, Edge, or Angle.

• Nominal Size: Enter the nominal size of the dimension you're measuring. This is the intended or target size.

• Actual Size (optional): If you have an actual measurement, you can enter it here for comparison.

• Tolerance Class: Choose the appropriate tolerance class - Fine, Medium, Coarse, or Very Coarse.

Results: Upon clicking "Calculate," the tool provides you with the following information:

• Tolerance Value: The calculated tolerance value based on the input parameters.

• Allowable Dimension Range: The range within which the dimension is considered acceptable, indicated by upper and lower limits.

• Comparison with Actual Size: If provided, the tool compares the actual size with the tolerance range and indicates whether it falls within tolerance or deviates, along with the deviation amount.

What is ISO 2768?

ISO 2768 is a standard that deals with general tolerances for linear and geometric dimensions in technical drawings.

The standard includes different classes of tolerances, ranging from "fine" to "very coarse," depending on the required precision of manufacturing. For example, there are tolerances for lengths, widths, thicknesses, and other dimensions of components. This norm helps ensure that products have consistent quality standards and are compatible with each other.

ISO 2768 is divided into two parts. The first part, ISO 2768-1, addresses general tolerances for length and angle measurements. Acceptable deviations are specified without the need for specific tolerance for each individual dimension. The second part, ISO 2768-2, establishes standards for tolerances regarding form and position.
In 2021, ISO 22081 replaced ISO 2768-2 as the standard for tolerances related to form and position without individual tolerance indications.

With my tool, you can verify both length measurements, fillet radii, chamfer heights, and angle measurements according to ISO 2768-1.