The Slope Rating reflects the relative difficulty of a course for players who are not scratch golfers in comparison to scratch golfers. Golfers use the Slope Rating, a trademark of the United States Golf Association, to calculate handicap differentials. The rating falls between 55 and 155; the higher the number, the more challenging the course. Bunkers, obstacles on the course, water hazards and trees are among the factors that can influence a Slope Rating. Golfers typically don't have access to the information used to calculate the Slope Rating, but understanding the formula makes the rating less confusing.
Use the Bogey Rating of the course. Ask at the golf course or contact the regional golf association that did the on-site rating. The golf pro or general manager should be able to tell you which golf association brought a rating team to the course. The Bogey Rating is indicative of the number of strokes a bogey player — for men, a handicap of about 20; for women, a handicap of about 24 — is likely to take to play the specific course in good weather conditions. Effective playing length, yardage and obstacles are among the factors used to figure the Bogey Rating, which is taken to one decimal place. The rating team spends a day walking the golf course, hitting shots from different areas and calculating the difficulty with a USGA handbook.
Locate the USGA Course Rating. The rating for each set of tees is usually on your scorecard, or you can ask staff at the course for this information. The course rating reflects the number of strokes — to one decimal place — a scratch golfer should take to play the particular course in favorable weather. Yardage and obstacles also are used to determine this rating.
Subtract the Course Rating from the Bogey Rating. For example, if a golf course has a Bogey Rating of 92.1 and a Course Rating of 70.1, subtract 70.1 from 92.1 for a difference of 22.
Multiply the difference between Course Rating and Bogey Rating according to gender. For male golfers, multiply the difference by 5.381; for women, multiply it by 4.24. Round to the nearest whole number. This is the Slope Rating. With a difference of 22 between the Bogey Rating and Course Rating, the Slope Rating is 118 for a man and 93 for a woman.