 <p>You can use the <a href="http://www.tcl.tk/man/tcl8.4/TkCmd/scale.htm" rel="nofollow"><code>-resolution</code></a> option:</p> <pre><code>#!/usr/bin/wish package require Tk scale .meter -from 0 -to 10 -variable r -label meter -orient horizontal -resolution 0.1 pack .meter -fill both -expand true </code></pre> <p>Will take all increment/decrement by 0.1.</p>