Green Speed and the Stimpmeter, What the Numbers Mean and How to Measure at Home
How Stimpmeter readings work, what speeds real courses run, how to build and use a DIY ramp on your own green, and how infill and brushing move the number.
On this page
This page is for golfers who want their home green to match the courses they play. You will learn what Stimp numbers mean, how to measure your own green fairly, and which adjustments move the speed up or down.
What is a Stimpmeter?
The Stimpmeter is a simple device for measuring green speed, originally devised by Edward Stimpson in the 1930s and later adopted and standardized by the USGA. It is an aluminum bar about 36 in long with a V-shaped groove and a notch about 30 in from the end that rests on the green. You place a ball in the notch and slowly raise the bar. At about 20 degrees, the ball releases and rolls down the groove onto the green.
Because the ball always leaves the ramp at nearly the same speed, the distance it rolls depends on the surface. That distance, in feet, is the Stimp reading.
What do Stimp numbers mean?
| Stimp reading | Description | Where you see it |
|---|---|---|
| Under 7 | Slow | Some municipal courses, wet or shaggy greens |
| 8 to 10 | Medium | Many public and daily-fee courses |
| 10 to 11 | Medium-fast | Well-kept private clubs |
| 12 to 13 or more | Fast | Professional tournaments, firm championship setups |
These are typical figures that vary with season, weather and maintenance. Each extra foot of Stimp makes a noticeable difference in how firmly you strike a putt and how much break you play.
Why speed and slope must be matched
A faster green magnifies every slope. A 3 percent slope that is playable at Stimp 8 may not let a ball stop near the hole at Stimp 12. If you plan a fast home green, keep cup areas close to flat; see the contour advice in the backyard putting green guide.
How do you measure green speed at home?
You can buy a Stimpmeter, or build a ramp that gives repeatable results. The official procedure is the same either way.
Building a DIY ramp
- Take a straight 36 in length of aluminum angle or two parallel rails that cradle a golf ball in a V.
- Mark a release point 30 in from the bottom end.
- Bevel or file the bottom end so it sits flush on the turf, reducing the bounce as the ball leaves the ramp.
- Make a stop or prop so you can raise the release point to the same height every time. On a 36 in ramp, raising the bar to about 20 degrees puts the 30 in mark roughly 10.25 in above the surface (30 x sin 20 degrees).
A homemade ramp will not exactly match an official Stimpmeter, because groove shape and the release mechanism affect launch speed. Treat your readings as consistent for your own green rather than directly comparable with a course. If you can borrow an official Stimpmeter once, roll both on the same flat section and note the difference as a correction factor.
The measuring procedure
- Find the flattest 10 to 15 ft section of the green. Check it with a level.
- Place a tee at your starting point.
- Roll three balls in one direction from the same spot. Mark where each stops.
- If the three balls finish more than about 8 in apart, the reading is unreliable: reposition and repeat.
- Measure from the bottom of the ramp to the midpoint of the three balls. That is the reading in that direction.
- Turn around and roll three balls back from the midpoint toward the start. Measure again.
- Average the two directions.
How does sand infill change putting green speed?
On a sand-filled green, infill is the main speed control.
- More sand, closer to the fiber tips: fibers are supported upright and the ball rolls on a firmer surface, usually faster.
- Less sand: fibers lean and the ball drags through them, usually slower.
- Uneven sand: creates fast and slow patches, so keep it level.
Add sand in thin passes and re-measure between passes. It is far easier to add sand than to remove it. Our infill calculator helps you estimate how much a top-up requires, and how to apply infill covers technique.
How does brushing and rolling change speed?
- Brushing against the grain lifts fibers and redistributes sand. Immediately after, the green can play slower until it settles.
- Brushing with the grain lays fibers in one direction and can make the green faster with the grain and slower against it.
- Rolling with a lawn roller firms the surface and generally increases speed.
- Moisture from dew, rain or irrigation slows any green until it dries.
- Heat can change speed slightly as fibers soften.
For routines that keep speed stable, see putting green maintenance and general brushing and grooming.
What speed should a backyard green be?
Our rule of thumb: set your home green to within 1 foot of the courses you play most. If they run 9 to 10, aim for about 10. Practicing on a much faster green can make you tentative on slower greens, and the reverse can make you aggressive.
| If your green reads | Likely cause | Adjustment |
|---|---|---|
| Below target | Low sand, fibers leaning, moisture | Add sand in thin passes, roll, let dry |
| Above target | Heavy sand, compacted, very dry | Brush against the grain, wait before rolling |
| Different by direction on flat ground | Grain, uneven sand, base tilt | Brush cross-grain, even out sand, check level |
| Changing week to week | Sand migrating, weather | Weekly brush, monthly speed check |
Our speed log method
Speed drifts slowly, so a single reading tells you little. Keep a simple log: date, weather, last brush, last sand top-up, both directional readings and the corrected speed. Over a season you will see how your green responds to each change and how long a top-up lasts. That record is more useful than any published speed claim for your turf.
Frequently asked questions
How fast are the greens at major championships?
Professional tournament greens are often prepared to around 12 to 13 or faster, depending on firmness, weather and course design. Some championship venues are known for very fast settings on firm days. The exact numbers are set by course officials for each event, so readings vary from round to round and year to year.
Can a synthetic putting green be as fast as a tour green?
Yes, many sand-filled and nylon synthetic greens can be set up at 12 or higher. The challenge is that very fast speed requires very gentle contours and a perfectly flat base, otherwise balls will not stop near the cups. For most home practice, a moderate speed with real break is more useful than maximum pace.
Does temperature affect putting speed on turf?
Somewhat. On hot days, synthetic fibers soften slightly and dew is absent, which can make a green feel a touch faster or slower depending on the product. Morning dew slows a green noticeably until it evaporates. Measure at a consistent time of day so you compare like with like when tracking changes.
Is a phone app accurate for measuring green speed?
Some apps estimate speed from ball roll timing or video, and they can be useful for tracking relative changes on your own green. Their accuracy depends on setup and camera angle. A consistent physical ramp and tape measure give you a more repeatable reading, which is what matters when you are adjusting sand and brushing.