Golf Glossary
Stimpmeter (Green Speed)
In short
The Stimpmeter is a device that measures the speed of a green. An inclined channel releases a ball at the same speed every time. The distance it rolls on a flat green gives the stimp reading in feet. A reading of 10 means about three metres of roll. The higher the number, the faster the green.
Stimpmeter: the meaning explained
Every green rolls differently. On some greens the ball runs long and evenly, on others the turf slows it quickly. So that golfers and greenkeepers do not only talk about this by feel, there is the Stimpmeter. It measures green speed as a number.
The device is a narrow track with a groove in which a golf ball sits. When the track is raised, the ball rolls down from a notch, always at the same speed. Then it rolls across the green and eventually stops. The distance to that point, measured in feet, is the stimp reading. One foot equals about 30.5 centimetres.
A stimp of 10 therefore means the ball rolls about 10 feet, around 3 metres. A reading of 8 stands for a slow green, a reading of 12 for a fast one. In everyday talk golfers say the green stimps at 10. The word stimp is short for the name of the device.
History: who invented the Stimpmeter?
The Stimpmeter goes back to Edward S. Stimpson, an amateur golfer from Massachusetts. According to tradition he saw at the 1935 US Open at Oakmont how a putt rolled far past the target because of very fast greens. He wanted to make speed measurable and built a device with a groove that let the ball run off the same way every time. Early versions were made of wood.
For a long time the device remained an idea for insiders. In 1976 the American golf association, the USGA, redesigned it and built it from aluminium. In the same year it made its national championship debut at the US Open. After that it spread among greenkeepers and became the standard.
Today the Stimpmeter is widespread in the golf world. Greenkeepers use it to steer maintenance and tournament organisers to keep greens comparable. The exact dimensions of the device are set by the USGA.
How the measurement works
Today's Stimpmeter is an aluminium track about 91 centimetres long with a V-shaped groove. At one end it has a notch from which the ball starts. The notch lies about 76 centimetres from the narrow end. The track is raised until it is tilted at about 20 degrees. Then the ball rolls off.
The procedure runs in several steps.
- Choose a spot on the green that is as flat as possible, with enough free run.
- Roll three balls in turn from the notch. They should stop close together.
- Determine the average of the distance.
- Repeat the whole thing in the opposite direction.
- Average both values so that a slight slope does not distort the result.
The Stimpmeter only measures on a flat surface. It does not capture the slopes of a green. The measurement is therefore a guide to pace, not a substitute for the player's feel.
Typical stimp readings: slow, medium, fast
The number alone says little if you cannot place it. As a rough guide:
- Around 8: slow greens, often on courses with heavy play or in wet conditions.
- Around 10: medium pace. Many recreational golfers play on greens between 8 and 10.
- Around 12 and more: fast greens, as usual at professional tournaments.
The values are guidelines. Each course decides how fast its greens should be. Fast greens are harder to play and need more maintenance. For recreational players slower greens are often more pleasant, because putts are easier to judge and play stays fluid.
The reading of a green also changes from day to day. A green can be slower in the morning with dew than in the afternoon, and slower after rain than after a dry week. The Stimpmeter therefore only shows the state at the time of measurement.
What influences green speed
Several factors determine how fast a green rolls.
- Cutting height: the shorter the grass, the faster the ball rolls. As a rough guide, greens are mown to about three to four millimetres.
- Mowing frequency and rolling: frequent mowing and rolling make the surface smoother and faster.
- Moisture: wet grass slows the ball, dry grass lets it roll.
- Grass type and growth: different grasses and growth directions change the roll.
- Time of day and weather: wind, sun and temperature have an effect.
- Fertilisation and firmness of the soil: a firm base rolls better than a soft one.
Greenkeepers manage these factors to keep the pace consistent. Professionals also take care that the greens of a course are similarly fast. Otherwise a player would have to rethink at every green.
Example from practice: the same putt on two greens
Take a putt of three metres on a flat green. On a green with a stimp of 8 you hit the ball with a certain strength and it rolls three metres. With exactly that stroke the ball rolls clearly further on a green with a stimp of 11, about four metres. The roll grows roughly in proportion to the stimp reading. The result: on the faster green the putt would be too long.
The same applies the other way round. Anyone who moves from a fast green to a slow one and plays the same stroke will leave it short. A simple rule helps with the adjustment: on fast greens take a shorter backswing and strike more gently, on slow greens take a longer backswing and hit more firmly.
On slopes the effect increases. A downhill putt on a fast green is considered especially difficult because the ball is hard to stop. The numbers are a worked example. They show why players check the pace on the practice green before the round.
How to adjust: play a few long and short putts on the practice green before the round. Practise length first, then direction, because pace matters more than line on most putts. Watch how far your putts roll on the first green. Anyone who plays regularly on one green develops a secure feel for its stimp. The number helps with comparing, but learning happens with the club in your hand.
Comparison: Stimpmeter, green and putting green
The Stimpmeter is a measuring device, not a playing element and not a term from the Rules of Golf. The rules do not set a particular green speed. How fast a green is is decided by the course.
The green itself is the area where the hole lies. The stimp reading describes its property, not its size or shape. The slopes and humps of a green are called contours. The curve a putt takes because of them is what golfers call break. A green can therefore be fast and flat or slow and strongly sloped.
The putting green in the sense of a practice area is the facility for practising, usually near the clubhouse. Its pace often matches that of the greens on the course, but not always. If in doubt, ask whether the practice green is similarly fast. Putting mats for home also roll at different speeds. Manufacturers often state a stimp reading for them.
Try it at Golf Lounge
The feel for pace and line when putting can be trained in a targeted way with a PGA pro. At Golf Lounge Resort Hamburg you book a single lesson of 60 minutes online, daily by appointment. Besides single lessons there are short impulse sessions, for example on short game and putting. After a course or lesson the PuttView green can be added, an augmented reality system that projects the putting line, pace and green contours onto the green.
Frequently asked questions
What is a Stimpmeter?
A Stimpmeter is a device for measuring the speed of greens. An inclined channel releases a ball at the same speed every time. The distance the ball rolls on a flat green gives the stimp reading in feet. The further the ball rolls, the faster the green. Greenkeepers use the device for maintenance.
What does a stimp of 10 mean?
A stimp of 10 means that after leaving the Stimpmeter the ball rolls about 10 feet on a flat green, around 3 metres. As a rough guide, values around 8 count as slow, around 10 as medium and 12 and above as fast.
How fast are greens on golf courses?
Many recreational golfers play on greens with stimp readings between about 8 and 10. At professional tournaments greens are often faster, frequently 12 or more. Each course decides the pace itself, and it also changes with weather and maintenance.
Who invented the Stimpmeter?
The Stimpmeter goes back to Edward S. Stimpson. According to tradition he developed it after the 1935 US Open at Oakmont. The USGA redesigned the device in 1976 and used it at that year's US Open. After that it became the standard. Today greenkeepers use it worldwide.
What does the speed of a green depend on?
The main factors are cutting height, mowing frequency, rolling, moisture, grass type and weather. The shorter and drier the grass and the smoother the surface, the faster the ball rolls. Greenkeepers manage these factors to keep the pace consistent. Time of day and wind also play a part.
As of: October 2026