Digital Slide Rule Logo

A virtual slide rule for mobile and desktop

*** FREE! ***

Slide rules were used for over 400 years for calculating and estimating. They were finally abandoned with the advent of hand-held calculators, computers and smart phones. Their elegant simplicity is still a thing of wonderment. This program replicates the most common types of slide rules: Straight, circular, spiral and cylindrical. Dozens of scales are included and numerous features that could never exist on a physical slide rule are also included, such as color options, numeric displays of the values under the hairlines, and so on.

Slide rules were used to go to the moon and to build bridges, skyscrapers, tunnels, aqueducts and nearly everything else. Slide rules were simple to use and accurate enough for most applications.

Please note that this program is processor-intensive and with heavy use on mobile devices and laptops, may drain the battery fairly quickly. Every effort has been made to make the program efficient, but nevertheless, some functions take a few moments to occur, including initial load, which can take three or four seconds, or perhaps a little longer. Over 37,400 "nibs" are created during this time, as well as over 4,200 labels, so please be patient!

Because of all the detail, it looks best and runs best on a large-format machine such as a tablet. Also because of all the detail, the 30-loop spiral slide rule converts to a low-rez "bitmap data image" while you move it, then back to a "vector based image" as soon as you release.

Includes a slide show of famous and interesting slide rules, most of which are in the author's collection. Two are public-domain photographs of antique slide rules.

Use the online version here (requires Ruffle, the web-friendly, free, open-source Adobe Flash Player emulator):
(The above online version is not recommended for mobile devices (please download a free app instead (see below))

To download an installable version for PCs:

To download a "zip" version for Apple Macintosh and Linux systems:

Mobile app versions are available through these resources:

To find the program at the Google Playstore:

To find the program at the Apple App Store:

Program may take a few moments to download and install; please be patient!)

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Made In USA Flag Our software is hand-crafted in the U.S.A.

Last modified MMXIX
Webmaster: Ace Hoffman
Copyright (c) Ace Hoffman