Tolerance Stack-Up Calculator

Tolerance Chain Visual

Hover over the image for a detailed view.

1. Chain Components

Enter each dimension and its sign convention as it affects the final gap. If increasing the dimension reduces the gap, use the negative sign; if it increases the gap, use the positive sign.

2. Analysis & Results

The final calculated gap based on a Worst Case summation.

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Gap Range by Method

Method

Min Gap

Max Gap

Worst Case

RSS (±3σ)(Normal; 99.73% Conf.)

RSS assumes independent contributors with normal distribution; each asymmetric band is treated as ±3σ, so σ = band width / 6.

Detailed Stack-up

+	-	Tolerances

ISO 286/2768 Tolerance Assistant

Find ISO tolerance limits for a dimension.

Precision:

Enter a dimension to see limits.

Frequently Asked Questions

What does the Tolerance Stack-Up Calculator do?

It calculates the cumulative effect of individual part tolerances in an assembly using Worst Case and RSS (Root Sum Square) methods.

What is the difference between Worst Case and RSS?

Worst Case assumes all tolerances occur at their maximum simultaneously. RSS uses a statistical model where tolerances combine as the square root of the sum of squares, giving a more realistic result.

Is the Tolerance Stack-Up Calculator free?

Yes. This tolerance stack-up calculator runs in the browser and is completely free — no installation or registration needed.