1RM is a Mac OS X Dashboard widget that calculates your maximum possible lift (1RM, “one-rep max”) given the number of times a submaximal lift weight was lifted. For convenience, it also lists simple percentages of the 1RM calculated and a suggest number of reps for that weight.
The formula used to calculate the one-rep maximum is:
1RM = wt / (0.997568 - 0.0248505 * r)
wt is the weight lifted
Installation is straightforward. Here are Apple’s instructions:
Mac OS X 10.4 Tiger is required. If you’re using Safari, click the download link. When the widget download is complete, show Dashboard, click the Plus sign to display the Widget Bar and click the widget’s icon in the Widget Bar to open it. If you’re using a browser other than Safari, click the download link. When the widget download is complete, unarchive it and place it in
/Library/Widgets/in your home folder. show Dashboard, click the Plus sign to display the Widget Bar and click the widget’s icon in the Widget Bar to open it.
- Version 1.3, March 2009 (download)
- Enforced limits of 0-10 reps.
- Version 1.2, January 2009 (download)
- Tweaked formula to ensure 1RM is equal to weight when reps is 1; upgraded to fully Leopard-compatible (cosmetic differences).
- Version 1.1, June 2006 (download)
- Cleaned up interface.
- Version 1.0, May 2006 (download)
- Original version.