Golf Handicap Calculator
The World Handicap System made one number the currency of amateur golf: the differential, (113 ÷ slope) × (adjusted gross score − course rating). It is the only fair way to compare a 95 at a brute 74.8/140 course with a 95 at a friendly 69.9/113 one - and it is the raw material your index is made of, being the average of your best 8 differentials from the last 20 rounds.
This calculator runs the differential from any scorecard in one line, then answers the question you actually have on the first tee: with your index entered, it gives the course handicap for today's rating and slope, the target score that counts as a 'handicap round', and whether today beat your index. Inputs are remembered for league night, and the share link carries your round.
How to use
- Enter your adjusted gross score plus the course's rating and slope from the card.
- Add your handicap index and par to get today's course handicap.
- Play to par + course handicap - that's a net-even round on any course on earth.
Frequently asked questions
How is a handicap differential calculated?
Differential = (113 ÷ slope rating) × (adjusted gross score − course rating). The 113 is the baseline slope: shoot 95 from a 72.4 rating on a 128-slope course and your differential is (113/128) × 22.6 ≈ 19.9. Harder courses shrink the number, which is exactly the point.
How does my handicap index come from differentials?
Your index is the average of your lowest 8 differentials from the most recent 20 acceptable rounds (fewer rounds use a scaled table), multiplied by 0.96 - a small nod toward your potential rather than your average. It updates as new scores post, which is why a great day shows up in your index within days.
What is a course handicap and why does it differ from my index?
Course handicap = index × (slope ÷ 113) + (course rating − par). It converts your portable index into strokes for one specific set of tees on one specific course - more strokes on a harder-than-average layout, fewer on an easy one. It's the number you play with, not the number on your profile.
Does a disaster hole ruin the round's differential?
No - the system caps every hole at net double bogey for handicap purposes ('adjusted gross score'), which is why the input says adjusted: pick up, take the cap, and one triple-quadruple costs you almost nothing in differential terms. The best-8-of-20 averaging handles the rest.