# Kiessig Thickness Calculator Tool

## Description

This tool estimates real space dimensions from the position or spacing of features in reciprocal space. In particular a particle of size \(d\) will give rise to Bragg peaks with spacing \(\Delta q\) according to the relation

\[d = 2\pi / \Delta q\]

Similarly, the spacing between the peaks in Kiessig fringes in reflectometry data arise from layers of thickness \(d\).

## Using the tool

To get a rough thickness or particle size, simply type the fringe or peak position (in units of 1/Å) and click on the Compute button.

Note

This help document was last changed by Romain Conan, 12Nov2025