The regulation field is used for the Open, Under 18 and Under 16 age groups. A modified field is used for Little League and Under 14.

The playing field

The infield (also called diamond) is a 27.4m square and is graded so that the baselines and home plate are level. The infield and outfield, including the boundary lines, are fair territory and all other areas are foul territory.

The minimum distance from home base to the nearest fence, stand or other obstruction on fair territory is 76.2m. 

The pitcher’s plate is 10 inches above the level of home late. The degree of slope from a point 6 inches in front of the pitcher’s plate to a point 6 feet toward home plate is 1 inch to 1 foot and is uniform.

It is preferred that the line from home base through the pitcher’s plate to second base runs east‑­south-east.

Measurements of distances to the bases are as following:

  • Home base to second base 38.8m
  • Home base to first base 27.4m
  • Second base to first base 27.4m
  • Home base to third base 27.4m
  • Second base to third base 27.4m
  • First base to second base 27.4m
  • Distance between first and third base is 38.8m.

The foul lines and all other playing lines are marked with paint or non‑­toxic, non‑­burning chalk or other white material.

Home plate

Home base is a five‑­sided slab of white rubber. It is a 3.2cm square with two corners removed. This means one edge is 3.2cm long, two adjacent side are 21.5cm and the remaining two sides are 30.48cm and set at an angle to make a point.

The base is fixed in the ground level with the ground surface.


First, second and third bases are marked by white canvas bags or rubber covered bags, attached to the ground. The first and third base bags are entirely with the infield. The second base bag is centred on second base. The bags are 38.1cm square and filled with soft materials. 

Pitching mound and plate

The pitching mound is a 5.49m circle, centre of which is 18.39m from the rear of home plate. 
The pitcher’s plate is a rectangular slab of white rubber, 61cm by 15cm. It is set in the ground so that the distance between the pitcher’s plate and home base (the rear point of home plate) is 18.39m.

Baseball diamond field layout

Little League and Junior League

Playing facilities

The following are the minimum facility requirements for all levels of Little League and Junior League baseball under Baseball WA:

  • Base paths, including first base tramlines to be clearly marked.
  • First and third foul lines clearly marked for a minimum of 50m from first and third bases respectively.
  • Flagpoles, a minimum height of 1.5m are to be positioned at the extremities of the foul lines.
  • First, second and third bases and pitching rubber to be pinned.
  • Pitching mounds mandatory in all player grades.
  • Mandatory back net (minimum 4m wide and 3m high).
  • Designated dead ball line from edges of the back net and parallel to the first and third baselines (white marking is acceptable).
  • Home run fence using plastic cones is mandatory if a fence at the required distance is not available.

Age limitations for Little League and Junior League

Little League Major and All Star League9 to 12 years old inclusive
Little League Minor - player pitch (PP)8 to 12 years old inclusive
Little League Minor - machine pitch (MP)7 to 10 years old inclusive
Intermediate League11 to 13 years old inclusive
Junior League12 to 14 years old inclusive

Ground dimensions and set-up for Little League and Junior League

Ground dimensions and setup for Little League and Junior League
 Little League Major
and Minor-PP 
Little League Minor-MP Junior League 70 Junior League 80 and
JL All Stars 
Base paths 18.28m18.28m21.33m24.38m
Pitching distance14.02m14.02m15.24m15.24m
Home run fences/cones60m from home plate50m from home plate76.2m from home plate91.4 feet from home plate
Back net (recommended)Max 10m from home plateMax 10m from home plateMax 15m from home plateMax 15m from home plate


Australian Baseball Official Australian Baseball Rules 7th Edition 2014.

Baseball WA Little League/Junior League Club-ball By-laws 2014/2015. Little League Western Australia

Sport association details

Baseball WA Ltd

Lachlan Dale
Chief Executive Officer
PO Box 1489 Canning Vale DC WA 6970
Telephone 61 8 6336 7950
Facebook baseballwa


The information in this guide is general in nature and cannot be relied upon as professional advice concerning the design of, or marking out for, sporting facilities and playing areas. No assurance is given as to the accuracy of any information contained in this guide and readers should not rely on its accuracy. Readers should obtain their own independent and professional advice in relation to their proposed sporting activity.

Page reviewed 17 June 2021