What is a Stimpmeter?

A Stimpmeter is a simple grooved aluminium ramp that releases a golf ball at a fixed speed. The distance the ball rolls on a flat green, measured in feet, is the green speed reading, with higher numbers meaning faster greens.

What Stimpmeter readings are slow, medium, and fast?

Roughly, under 7 feet is slow, 7 to 9 is medium, 9 to 11 is fast, and above 11 is tour-fast. Most everyday club greens sit between 8 and 10 feet, while major championship greens often run 12 feet or more.

How does green speed change my putting?

On faster greens you make a shorter, softer stroke for the same distance, and break plays a bigger role because the ball is moving more slowly near the hole. On slower greens you must hit firmer and allow for less break.

Why measure on a flat section?

Slope corrupts the reading because gravity speeds up or slows the ball. The Stimpmeter protocol rolls balls in two opposite directions on a level area and averages them to cancel out any residual slope and wind.

Do the uphill and downhill adjustments depend on speed?

Yes. The faster the green, the more a downhill putt runs out and the more an uphill putt dies, so the pace adjustment grows with speed. The tool scales the suggested stroke change with the Stimpmeter reading.

Golf Green Speed (Stimpmeter) Calculator

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Green speed decides how hard you must hit every putt, and the Stimpmeter puts a number on it. This calculator classifies a Stimpmeter reading and tells you how to adjust your pace for uphill and downhill putts on that surface.

How it works

The reading in feet maps directly to a speed class, and the pace adjustment scales with that speed:

< 7 ft   Slow
7–9 ft   Medium
9–11 ft  Fast
> 11 ft  Tour-fast

faster green -> softer stroke, more break
downhill putt -> reduce stroke (scaled by speed)
uphill putt   -> add to stroke (scaled by speed)

Because a faster green keeps the ball rolling longer, slope has a larger effect, so the downhill and uphill adjustments widen as the Stimpmeter reading rises.

Example and tips

A reading of 10.5 feet classifies as fast and calls for a noticeably softer stroke than an 8-foot club green; downhill putts on it might need roughly a third less stroke and uphill putts a third more. Always take the reading on a flat area in two directions and average, and remember that grain, moisture, and afternoon firmness can push real speed above the morning measurement.