Course Rating represents the difficulty of a golf course for a scratch golfer (0 Handicap Index), calculated to the nearest 0.1.
Slope Rating represents the relative difficulty of a course for a bogey golfer (20 to 24 Handicap Index) compared to a scratch golfer.
A course with long carries, narrow fairways, lots of hazards and thick rough will have a high slope rating because these features are more of a challenge to bogey golfers.
Slope Rating can be anywhere between 55 and 155. 113 is the neutral value that is used in handicap calculations. The GB&I average Slope Rating is 125.
You can look up the ratings for other courses anywhere in the World on the USGA course rating & slope database.
A golfer's handicap for a specific course is determined by multiplying their Handicap Index by the Slope Rating and dividing by 113, as described on the Course and Playing Handicaps page.
How Slope Ratings are calculated
MEN
A male scratch golfer is defined as someone who hits the ball about 250 yards with a driver and 230 yards with a fairway wood. The England Golf course assessors calculate what a male scratch golfer should average on the course.
A male bogey golfer is defined as a typical 20 handicapper who hits the ball about 200 yards with a driver and 170 yards with a fairway wood.
Subtracting the Scratch Rating from the Bogey Rating and multiplying by a Constant of 5.381 gives the Slope Rating
WOMEN
A female scratch golfer is defined as someone who hits the ball about 210 yards with a driver and 170 yards with a fairway wood.
A female bogey golfer is defined as a typical 24 handicapper who hits the ball about 150 yards with a driver and 130 yards with a fairway wood.
Subtracting the scratch rating from the bogey rating and multiplying by a Constant of 4.240 gives the Slope Rating.