PuttCalc is a free online, mobile-friendly, golf training aid that simulates and solves putts on a theoretical, flat, tilted green. Its purpose is to improve your ability to read greens by being better able to identify the factors that influence the putt, and to determine the line and speed needed to hole the putt.
The inputs to the application for an individual putt allow you to change the values of many variables that affect the roll of the golf ball:
- Green Speed (Stimp)
- Slope
- Ball Position (relative to the hole and to the Fall Line)
- Grain
- Wind
- Overrun Distance
- Target Line*
- Ball Speed*
* In either auto mode, PuttCalc will find the optimum line and speed for you.
Furthermore, the settings allow you to tune more subtle factors that affect putts.
This application is intended for practice and for self-study. It is not intended for competition, nor for handicap-recordable rounds.
The flat green simulations on this site are meant to help you with real greens, which are not uniformly flat, though the areas around the holes can often be treated that way. Greens have many subtle, and sometimes not so subtle, changes in elevation, and curved contours. Feel, intuition, visualization, and experience are integral parts of putting. In addition to the line, this application can help you estimate the speed needed for a putt, but it is up to you translate the speed requirement into physical action.
Regarding how to use this site, check out the How To page for some sample screen images. See also the Manuals page for access to the free downloadable user manuals.
If you want to just jump straight in, then click the red PuttCalc link above.
A revised book based on PuttCalc, by the inventor of this site, is in progress. It will provide green reading training guidance and insights. See the Books page for more info.
The main audience for this site and the book(s) is golfers and caddies, but many others involved with golf may also find them to be of interest.