Golf, worked out in numbers
Turn a guess about the green
into a number you can trust
A physics-based calculator for putting break and pace, plus articles on how to read greens.
Tools
Tools that put numbers behind your decisions on the green. Everything is computed in your browser.
Putt Break Calculator
Works out how much a putt breaks, and the pace and aim that hole it, from the distance, slope and green speed. View the path in 3D and get the stroke most likely to go in.
- Putting
- 3D
- Physics
Carry Range Finder
Simulates the ball flight to show how much each club’s carry changes with temperature, altitude, pressure, humidity, wind and elevation — and which club it effectively plays like.
- Full swing
- Ball flight
- Wind & altitude
Green speed log
Coming soonLog the green speed and putt count for each round and review how your touch trends over time. Coming soon.
- Logging
- Coming soon
Blog
Notes on reading greens and the physics of putting.
The three things to look at first when you read a green
Checking slope, green speed and the last metre before the hole — in that order — sharpens your line more than anything else. Here is why, with the physics behind it.
- Putting
- Green reading
- Fundamentals
Is it better to "hit it firm" or to "play the line"?
There is a trade-off between how much pace and how much direction you are allowed to miss by. Starting from the speed at which a cup can capture a ball, we work out which touch holes the most putts.
- Putting
- Pace
- Probability
The first 20% of a putt is not rolling at all
Straight after impact the ball is airborne, then sliding. That phase is exactly why a putt barely breaks early on.
- Putting
- Physics