Pitching mound dimensions are tightly specified for good reason: an inch of extra height or a slope that falls off too fast changes a pitcher’s mechanics and a batter’s timing. The regulation numbers for a full-size mound are 10 inches of height, an 18-foot diameter and a rubber set 60 feet 6 inches from the back point of home plate, with the front slope dropping one inch per foot. Youth levels scale those down. Getting the numbers right is only half the job; the mound also has to tie into the surrounding grade, which is where a well-built mound and a well-built turf infield installation have to meet cleanly.
Regulation pitching mound dimensions
The Official Baseball Rules used by MLB set the standard that college (NCAA) and high school (NFHS) rulebooks follow for the full-size diamond.
| Element | Regulation specification |
|---|---|
| Pitching distance | 60 feet 6 inches from the rear point of home plate to the front edge of the pitcher’s plate |
| Mound height | Top of the rubber is 10 inches above the level of home plate |
| Mound diameter | 18-foot circle, center 59 feet from the rear point of home plate |
| Pitcher’s plate (rubber) | 24 inches wide by 6 inches deep, set flush with the table |
| Level table (plateau) | Extends 6 inches in front of the rubber, 18 inches behind, and 24 inches to each side: about 5 feet by 34 inches |
| Front slope | Begins 6 inches in front of the rubber and falls 1 inch per foot for 6 feet |
| Remaining slope | Gradual and uniform from the end of the 1-inch-per-foot section to the edge of the circle |
The 1-inch-per-foot slope is the detail most often built wrong; it is measured with a slope board or string line, not eyeballed. Because the rubber sits 18 inches back from the circle’s center, there is more mound in front of it than behind.
Pitching mound size and distance by level
Youth organizations scale the distance and height to the pitcher; the slope principle stays the same.
| Level | Pitching distance | Mound height | Mound diameter |
|---|---|---|---|
| MLB, NCAA, NFHS high school | 60 ft 6 in | 10 in | 18 ft |
| Little League Junior and Senior (full diamond) | 60 ft 6 in | 10 in | 18 ft |
| Little League Intermediate (50/70) | 50 ft | 8 in | 10 to 18 ft, often 15 ft |
| Little League Major and below (60-foot bases) | 46 ft | 6 in | 10 ft |
| Fastpitch softball | 43 ft (women) or 46 ft (men); no mound | Flat | 16-ft pitching circle at grade |
For how base paths, fences and mounds scale together as players grow, see our page on youth baseball field dimensions by age.
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Building a pitching mound
A mound is a compacted clay structure built in layers and finished with a high-clay surface in the landing and push-off zones.
- Locate the center and the rubberMeasure 59 feet from the rear point of home plate for the circle’s center and 60 feet 6 inches to the front of the rubber, squared with a string line.
- Build the base in liftsAdd 2 to 3 inches of mound clay or heavy infield mix at a time, moisten and tamp each lift fully. Compaction is what keeps the mound from sinking.
- Set the rubberAnchor the pitcher’s plate so its top is exactly 10 inches above home plate (or the level’s spec), checked with a transit or laser level.
- Shape the table and slopeForm the 5-foot by 34-inch table, shape the front slope with a slope board at 1 inch per foot for 6 feet, then feather to the circle’s edge.
- Finish the landing and push-off zonesPack clay bricks or high-clay mound mix several inches deep in front of the rubber and in the landing area, then cap with mound clay.
Pro tip: mounds drift over a season as holes are filled. A weekly check with a tape and a level prevents a slow build-up that puts the rubber over height.
Pitching mound clay
Infield mix is engineered to drain and play fast; mound clay is the opposite, a high-clay material that packs hard and holds an edge. Bagged mound clay is tamped into the landing and push-off areas, or unfired clay bricks are laid in those zones, soaked, tamped and capped with loose clay for a surface that resists cleat holes far longer. Both need moisture to stay bound, which is why tarps and a hose are part of mound care.
Integrating a mound into a turf infield
More fields now pair a clay mound with a synthetic turf infield. The challenge is the transition: the mound’s slope has to run out into the surrounding grade without a lip or a soft ring where clay meets turf, and the turf’s drainage base has to stay sealed off from clay fines.
A concrete or composite collar at the 18-foot circle gives the turf a hard edge to be glued to and the clay a form to be packed against; the mound is built inside it after the turf is down. Some facilities choose a synthetic turf mound with a clay insert at the rubber and landing area. Indoor facilities commonly use a portable fiberglass or turf-covered mound that rolls onto the field; our page on indoor turf facilities covers how those surfaces are built.
Whichever approach, the grade has to be designed as one surface, or the mound slope ends up fighting the infield crown. The experienced installers we work with lay out the mound, bases and plate before the base is screeded so the whole infield drains and plays as one piece. If you are planning a turf infield with a clay or synthetic mound, talk with a vetted crew about professional turf installation and ask how they will detail the mound transition.
Pitching mound dimensions FAQ
How high is the pitching mound?
A regulation pitching mound is 10 inches high, measured from the top of the pitcher’s plate to the level of home plate. Little League Major mounds are 6 inches, and Intermediate 50/70 mounds are 8 inches.
What is the pitching mound distance?
On a full-size diamond the front of the rubber is 60 feet 6 inches from the rear point of home plate. Little League Major uses 46 feet and Intermediate uses 50 feet. Fastpitch softball pitches from 43 feet (women) or 46 feet (men) on a flat circle.
What is the slope of a pitching mound?
Starting 6 inches in front of the rubber, the mound falls 1 inch per foot for 6 feet, then slopes gradually and uniformly to the edge of the circle. The area around the rubber is a level table about 5 feet by 34 inches.
Can you put a clay pitching mound in a turf infield?
Yes. It needs a hard collar at the circle edge so turf and clay meet cleanly, a grade designed so the mound slope runs out into the infield crown, and protection for the turf’s drainage base from clay fines. Synthetic and portable mounds are alternatives.
The complete turf installation guide
What a quality install looks like, the eight installation steps, spec sheets, and how to choose an installer.