Do uphill putts break more or less? Less, and here's how much

Uphill putts break less, and downhill putts break more. On the same 2% side slope, a 10-foot putt needs about 8.6 inches of break when it runs 2% uphill and 15.2 inches when it runs 2% downhill, almost twice as much.

They break the same way, toward the low side. Only the amount changes, and it changes more than most golfers play. This post has the numbers for each slope, the reason behind them, a simple way to adjust on the course, and why uphill putts go in more often.

How much less uphill putts break

We ran a 10-foot putt across a 2% side slope on a Stimp 10 green through Plumb Bob's putt simulator. It models a ball rolling over a tilted green, slowed by the grass and pulled by gravity, hit at a pace that finishes about 17 inches past the hole. We changed only the slope along the putt:

Two things stand out. Uphill takes break off gently, about 10–13% for each 1% of grade. Downhill adds it fast, and faster the steeper it gets: the third percent of downhill adds nearly as much break as the first two together.

Length doesn't change those percentages. At 5 feet the same slopes give 3.5 inches uphill, 4.5 level and 6.2 downhill. At 20 feet they give 19.7, 25.2 and 34.9. At every length, 2% uphill is about a fifth less than level and 2% downhill about two-fifths more. You can check your own putts in the putt break calculator.

Which way do uphill putts break?

The same way as every putt: toward the low side, the way water would drain. If the green falls from left to right across your line, an uphill putt breaks right and so does a downhill one. Going uphill or downhill changes how much a putt breaks, never which way.

A putt straight up or straight down the slope, with no side slope at all, doesn't break. Most putts are a little off that line, though, and on a downhill putt a little side slope goes a long way. For the full direction routine, see how to tell which way a putt breaks.

Why uphill putts break less

It comes down to time on the slope. The side slope pushes the ball sideways the whole time it rolls, and the sideways drift grows with the square of that time.

Uphill, gravity helps the grass slow the ball, so you hit it firmer to get it to the hole. Downhill, gravity fights the grass and keeps the ball rolling, so you hit it softer. In the simulator, our 10-footer at Stimp 10 works out like this:

The downhill putt spends about 30% longer on the slope than the uphill one. Square that and you get about 70% more sideways drift, which is roughly the gap in the table. The extra time is spent near the hole, where the ball is slowest, so that's where a downhill putt does most of its turning.

Uphill is a slower green, downhill is a faster one

A handy way to think about it: grade changes the green speed the ball feels. On a Stimp 10 green, our 10-footer breaks like this:

So a 2% downhill putt on an ordinary club green breaks like a level putt on tournament-fast greens. If you play a faster course than usual, the two stack up, which we cover in do fast greens break more. At Stimp 12 the same putt needs 9.9 inches uphill and 20.1 inches downhill. At Stimp 8 it needs 7.1 and 11.2.

The trap: hit it like a short putt, read it like a long one

This is where struggling golfers lose the most strokes. Uphill and downhill change the pace and the break in opposite directions, and our instincts link the two the wrong way round.

Take the 10-footer on a 2% grade at Stimp 10. For pace, it plays like a different length: the downhill one needs about the stroke of a 7-foot level putt, and the uphill one about the stroke of a 13-footer (the numbers are in how hard to hit a putt). For break, it's the other way round:

The downhill putt feels small because the stroke is small, so we read it small too. It needs the break of a putt almost twice as long. Read it like the tap it feels like and it slides under the hole every time. The uphill putt is the reverse: a big stroke that needs a modest line. Play it with the same break as a level putt and the firm pace holds it on the high side.

Why uphill putts are easier to make

Tour players make more uphill putts. Mark Broadie, who created strokes gained, found in PGA Tour ShotLink data that eight-foot uphill putts are holed about 5% more often than eight-foot downhill putts, and that steep sidehill-downhill eight-footers go in almost 20% less often than their uphill-sidehill counterparts.

The main reason is the one above: an uphill putt is hit firmer, so it breaks less, and a misread costs less. In the simulator, if a 10-foot putt actually sits on 2.5% of side slope instead of the 2% you read, the right aim moves by 2.2 inches uphill, 2.9 inches level and 4.1 inches downhill. The hole is 4¼ inches wide. A 2-inch error can still catch the edge; a 4-inch error misses.

Broadie also found that there's no evidence golfers can reliably leave themselves more uphill putts, so his advice is to hit it closer to the hole rather than plan for the uphill side. Once you're on the green, how you lag each putt still matters: see how to stop three-putting.

How to play uphill and downhill putts

1. Decide uphill or downhill first. Before you read the break, look at the putt from the side, halfway along, and feel it with your feet. On a slope you can barely see, it changes everything after this step.
2. Read the side slope as normal. Your eyes, your feet and a plumb bob all read the slope. They don't see the grade's effect on break. A perfect plumb-bob read of our 10-footer shows the same 3.2 inches uphill, level and downhill, as we explain in plumb bob putting.
3. Scale it. Uphill, take off about a tenth for each 1% of grade. Downhill, add about a sixth for the first 1%, about two-fifths at 2%, and up to three-quarters at 3%. If that's too much maths, use cups: on a medium-speed green, a 10-footer that breaks 2½ cups level breaks about 2 cups uphill and 3½ cups downhill.
4. Set the pace for the plays-like distance. Firm uphill, soft downhill. Then keep that pace: if you decide to charge an uphill putt, play even less break; if you die a downhill putt in, play even more.
5. Give downhill putts extra on fast greens. Downhill on a fast green is where the break explodes, and it's where most low-side misses come from. Start it higher than looks sensible and let it fall.
6. Watch for grain on Bermuda. Putting down grain behaves like putting downhill: faster and more break. Into the grain behaves like uphill. See how to read grain on greens.

Most golfers under-read every putt, and downhill putts most of all, because nothing on a real green tells you the answer. Plumb Bob is a green reading app for iPhone that does. It reads the slope with the camera (most precisely on iPhones with LiDAR, and it works without), so you can read a putt yourself, check it against the measured line, and learn what a 2% downhill slider really needs. It measures slope, not grain. Use it on the practice green and in friendly rounds; in competition, devices that read greens aren't allowed under Rule 4.3. You get 3 free reads, then Plumb Bob Pro is $9.99 a month or $59.99 a year, with a free week for new subscribers.

FAQ

Do uphill putts break more or less?

Less. You hit an uphill putt firmer and gravity slows it down, so it spends less time crossing the slope. In Plumb Bob's simulator, a 10-foot putt across a 2% side slope needs 8.6 inches of break 2% uphill against 11.0 inches on the level, at Stimp 10.

Do downhill putts break more than uphill putts?

Yes, much more. The same 10-footer needs 15.2 inches of break 2% downhill against 8.6 inches 2% uphill. On a Stimp 12 green the gap grows to 20.1 against 9.9 inches.

Which way do uphill putts break?

Toward the low side, like every putt. If the ground falls to the right across your line, an uphill putt breaks right. Uphill only changes how much it breaks.

Do uphill putts break left or right?

It depends on the side slope, not on the uphill. Find which side of your line is lower and the putt breaks that way. A putt straight up the slope doesn't break at all.

Why are uphill putts easier?

You hit them firmer, so they break less and a misread costs you less. In PGA Tour data, eight-foot uphill putts go in about 5% more often than eight-foot downhill putts.

Should you hit uphill putts harder?

Yes. A 10-footer on a 2% uphill grade plays like about 13 feet on a medium-speed green, so hit it like a 13-footer. Then play less break than a level putt, because the firmer ball turns less.