How Is World Golf Handicap Calculated?

Handicap Index is central to Golf's World Handicap System, but how exactly is it worked out?

How to calculate golf handicap index
How to calculate golf handicap index
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Under the new World Handicap System (WHS), Handicap Index is the key number for golfers. It’s the base point from which to work out how many shots will be received or given on a particular course (Course Handicap), in a particular format (Playing Handicap). But just how is that Handicap Index calculated under WHS?

WHS calculates Handicap Index by taking an average of the best eight “score differentials” of a player’s 20 most recent score differentials on their scoring record. A score differential is the difference between a player’s adjusted gross score and the Course Rating, reflecting Slope Rating and playing conditions calculation on the day.

Adjusted gross score takes into account holes where a player exceeds their maximum score (greater than nett double bogey), it also takes into account when a player does not play a hole (a nett par is given) or does not complete a hole (a nett double bogey is given).

The Playing Conditions Calculation looks at how all players who have entered a score on a course have performed on that day, compared to their expected performance. At the end of each day’s play a playing conditions calculation will be made by the system.

When a new score differential is submitted, the Handicap Index is automatically recalculated and updated at the end of the day’s play, ready for use the following day.

If (for a player with 20 or more score differentials on their scoring record) that new score differential does not improve upon one of the previous best eight score differentials, nor does it bump out a counting score differential, (previously the 20th most recent,) Handicap Index will not be altered.

To prevent wild swings in handicap, the WHS provides caps – soft and hard – based on a player’s lowest Handicap Index in a one-year period. If upon the input of a new score differential, a player’s handicap goes three shots above the low index, further rises are reduced by 50%. (Soft cap.) If a player’s handicap moves 5.0 strokes above the low index in a 12-month period, after the application of the soft cap, it cannot rise any further. (Hard cap.)

Players new to golf or looking to obtain a first handicap will need to submit scorecards amounting to 54 holes. From those, an initial Handicap Index will be provided. This will be altered as new score differentials are recorded up to the point where 20 score differentials have been submitted to deliver a fully developed Handicap Index. The system will calculate a player’s exact Handicap Index to one decimal place.

Fergus Bisset
Contributing Editor

Fergus is Golf Monthly's resident expert on the history of the game and has written extensively on that subject. He is a golf obsessive and 1-handicapper. Growing up in the North East of Scotland, golf runs through his veins and his passion for the sport was bolstered during his time at St Andrews university studying history. He went on to earn a post graduate diploma from the London School of Journalism. Fergus has worked for Golf Monthly since 2004 and has written two books on the game; "Great Golf Debates" together with Jezz Ellwood of Golf Monthly and the history section of "The Ultimate Golf Book" together with Neil Tappin , also of Golf Monthly. 

Fergus once shanked a ball from just over Granny Clark's Wynd on the 18th of the Old Course that struck the St Andrews Golf Club and rebounded into the Valley of Sin, from where he saved par. Who says there's no golfing god?