GolfHandicapp

How Handicap Calculation Works

GolfHandicapp calculates your handicap index using the World Handicap System (WHS) methodology. This guide explains how it works.

Score Differential

Each round produces a differential that measures how you played relative to the course difficulty:

Differential = (Adjusted Gross Score − Course Rating) × 113 ÷ Slope Rating

  • Adjusted Gross Score: your actual score with a maximum per hole (net double bogey)
  • Course Rating: the expected score for a scratch golfer
  • Slope Rating: how much harder the course is for a bogey golfer (55–155, standard is 113)
  • 113: the standard slope, used to normalise across courses

A lower differential means a better round relative to the course difficulty.

Selection Table

Your handicap index is the average of your best differentials from your latest 20 rounds. The number used depends on how many rounds you have:

| Rounds available | Differentials used | Adjustment | |---|---|---| | 3 | Lowest 1 | −2.0 | | 4 | Lowest 1 | −1.0 | | 5 | Lowest 1 | None | | 6 | Lowest 2 | −1.0 | | 7–8 | Lowest 2 | None | | 9–11 | Lowest 3 | None | | 12–14 | Lowest 4 | None | | 15–16 | Lowest 5 | None | | 17–18 | Lowest 6 | None | | 19 | Lowest 7 | None | | 20 | Lowest 8 | None |

The adjustments for fewer rounds make the handicap more conservative until you have enough data.

Soft Cap and Hard Cap

These prevent your handicap from rising too quickly after a few bad rounds.

  • Soft Cap: if your calculated index exceeds your lowest index in the past 12 months by more than 3.0, only 50% of the excess above that threshold is applied
  • Hard Cap: your index can never exceed your 12-month low by more than 5.0

Example: if your best index in the last year was 10.0:

  • Calculated index of 12.5 → stays at 12.5 (within 3.0)
  • Calculated index of 14.0 → becomes 13.5 (soft cap: 13.0 + 0.5)
  • Calculated index of 20.0 → becomes 15.0 (hard cap: 10.0 + 5.0)

Playing Handicap

Your playing handicap is the number of strokes you receive on a specific course:

Playing Handicap = Handicap Index × (Slope Rating ÷ 113)

A course with a higher slope gives you more strokes. This is the number used for Stableford scoring.

9-Hole Rounds

Nine-hole rounds use their own course rating and slope rating (typically about half the 18-hole values). The differential is calculated the same way and counts toward your handicap index alongside 18-hole rounds.

Important note

GolfHandicapp provides an unofficial handicap index for personal tracking. For an official handicap, register with your national golf association (e.g. England Golf, USGA).