Every score you make in a round that meets the posting criteria goes into your handicap record, with one adjustment: you post your adjusted gross score, not the raw number on the card. That's the short answer. The single most useful takeaway is that you never decide which rounds "count" — you post them all, and the system picks your best 8 of the most recent 20. Skip a legitimate score and your handicap index stops reflecting your actual game.
What Actually Counts as a Postable Score
A score is postable when you play at least 7 holes, on a course with a current course rating and slope rating, under the Rules of Golf, and either in a competition or in a round you intended to score before you teed off. Solo rounds are generally not postable unless your authorized golf association allows them. Nine-hole scores are postable and combine with another nine-hole score to form an 18-hole total.
Your playing partner last Saturday asked whether his 94 from the white tees should go in. It should, assuming the round was played under the rules and he finished at least 7 holes. What he should not post is the 94 exactly as written. He needs his adjusted gross score first.
Adjusted gross score caps each hole at net double bogey, which is par plus any handicap strokes you receive on that hole, plus two. If you get one stroke on a par 4, your cap there is 7. If you get none, it's 6. Anything above the cap gets trimmed down before posting. This is why a blow-up hole doesn't wreck your index the way the raw score would.
From Scorecard to Handicap Index
Once you have your adjusted gross score, the system converts it into a score differential using course rating and slope rating. The formula is:
Differential = (Adjusted Gross Score − Course Rating) × 113 ÷ Slope Rating
Here's a worked example. You shoot an adjusted 88 at a course rated 71.4 with a slope of 128.
- 88 − 71.4 = 16.6
- 16.6 × 113 = 1875.8
- 1875.8 ÷ 128 = 14.7
That round's differential is 14.7. Do this for every posted round, then the handicap index takes your lowest 8 differentials from your most recent 20 and averages them. Multiply that average by 0.96 and you have your index. If your eight best differentials average 13.9, your index is 13.9 × 0.96 = 13.3.
Fewer than 20 scores changes the math. With 3 scores you use your lowest 1; with 8 scores you use your lowest 2; with 15 scores you use your lowest 6. The table scales up until you reach 20 scores and the full 8-of-20 rule applies. If you're tracking this yourself between rounds, our free golf handicap calculator at our free golf handicap calculator handles the differentials and the 8-of-20 selection without you rebuilding a spreadsheet.
Course handicap is a separate number you use on the day, and it comes from your index:
Course Handicap = Handicap Index × (Slope Rating ÷ 113) + (Course Rating − Par)
With a 13.3 index at that same 71.4/128 course with a par of 72: 13.3 × (128 ÷ 113) = 15.1, then add (71.4 − 72) = −0.6, giving a course handicap of about 15. That's the number of strokes you actually get in the game, and it's also what determines net double bogey on each hole.
Common Posting Mistakes
Posting the raw score instead of the adjusted gross score is the most frequent error, and it inflates your index. Posting only good rounds is the opposite problem, and it does the same thing in the other direction. Both defeat the purpose.
Another one: forgetting that slope rating is not difficulty in absolute terms. A 128 slope means the course plays harder for a bogey golfer relative to scratch than a 113-slope course does. Two rounds of 88 at different courses can produce differentials several strokes apart. That is the system working as intended.
If you play a course with an unfamiliar slope, don't guess. Look up the rating and slope on the scorecard or the course's listing before you post. Entering the wrong slope shifts your differential, and if you're close to a cutoff for a tournament flight, that matters. A quick pass through a handicap index calculator confirms whether a score moved your index or barely nudged it.
Finally, post promptly. Most associations expect scores entered the same day, and back-filling a month of rounds at once invites errors and, in some cases, a review from your committee.
Frequently Asked Questions
How many scores do I need to get a handicap?
You need a minimum of 3 postable 18-hole scores to receive a handicap index under WHS. With 3 scores, your index uses your lowest 1 differential. The full 8-of-20 calculation kicks in once you have 20 scores on record.
Do I post a score if I pick up on a hole?
Yes, as long as you complete at least 7 holes. For any hole you don't finish, record your most likely score, capped at net double bogey. If you pick up on a hole, that cap is what goes into your adjusted gross score.
Should I post a score if I play alone?
Under the current WHS rules, solo rounds are generally not postable unless your authorized golf association permits them. Check with your state or national association, since policies vary. If solo rounds are allowed, they still need to be played under the Rules of Golf.
What is the maximum score I can post on a hole?
Your maximum is net double bogey: par, plus any handicap strokes you receive on that hole, plus two. On a par 4 where you get one stroke, the most you can post is 7. Anything higher is reduced to that number before posting.