Understanding Slope for Golf Rangefinders

Not all Golf Courses are Flat
Not all Golf Courses are Flat

Any golfer who has played an even slightly hilly course knows that changes in elevation can greatly affect their game. These changes, if not properly taken into account, can be detrimental to your final score and in 2017 there is no reason why this should still be the case.

This is actually obvious to anyone from hacker to pro. We have all stood on an elevated tee and tried to guess just how many clubs difference it really makes. Of course, we usually get it completely wrong, hence the need for something that really tells us the difference that slope is going to make to the shot.

Golf equipment manufacturers know all about slope and have included features that are aimed at helping golfers compensate for these changes. If you are in the market for the best golf rangefinder with slope, it is important to understand just what it is and how the right golf rangefinder with slope can help take strokes off your game.

What Is Slope?

First, we need to specify just what kind of slope we are discussing. There is slope and slope! In golf, the term “slope” often refers to the proportional difficulty of a group of tees based off of high versus low handicapped golfers. “Slope” is then used as a relative score to communicate how difficult a set of holes are. we talk about the slope of a course (given as a number) and it is a relatively easy way of comparing courses and adjusting handicap from one course to another.

That’s not the kind of slope we’re discussing in this article.

The kind of slope we’re talking about here is the change in elevation between two points. Anytime you walk uphill or downhill you are walking up or down a slope. Think of triangle on its side and you’ll see a slope. On the course, we deal with this all the time because a shot that goes from one point to another that is at the same height is the exception rather than the rule. 

Of course, most of the time, this difference is really enough to worry about, especially when most of us can’t hit every club exactly the same distance every shot anyway. This doesn’t mean you should just forget about it altogether though.


Why Is Slope Important?

Slope is very important for any golfer to consider. This is because, while you may calculate the distance between you and the flag in a straight line, you do not hit the ball in a straight line. The ball is hit at an arc and with a trajectory that effects how far it actually goes. Even if the exact physics of ballistics are beyond you (and they are certainly beyond me!) the principle is easy enough to grasp.

After your shot hits its peak, it begins to fall. And as it falls it continues to move forward. Depending on the slope of the land, this could affect the distance of your shot anywhere from 20 to 50 yards. That’s no small change! 

A smart course architect actually uses this effect to trick the golfer. Well perhaps trick is too strong a word, but it is part of good golf course design to lure the golfer into thinking that he needs to hit it further or shorter and this is often done with subtle changes in elevation.

I think I might turn the slope function on today!
I think I might turn the slope function on today!

Therefore, knowing the slope at which you are hitting the ball is critical for determining club selection, velocity (how hard you hit the ball), and spin. In other words, pretty much all the criteria for hitting a good shot!

Balls will travel a shorter distance with positive (uphill) slope and a farther distance with negative (downhill) slope. Knowing just how much change in elevation occurs between you and the pin is extremely important and in all honesty, it is virtually impossible to do this by eye.

How Is Slope Calculated?

So, you might be thinking at this point, “Great, the green is ten yards higher than I am right now, that’s easy to account for!” But wait a second! Just because there is a ten-yard difference in elevation does not mean that the slope from you to the hole is ten yards!

It’s a bit more complicated than that. Remember all those times in Geometry class that you cried out, “When am I ever going to use this!?” Well, now would be one of those times. Bet you are glad you paid attention at school now, right? What? You didn’t? Never mind, here is the simple version.

To figure out just what club to use and how hard to hit the ball, you’d need to know the slope from you to the hole. And slope is calculated by dividing “Run” by “Rise.” This is actually something you can work out with a few (relatively) simple calculations, but the group behind you (and the ten groups behind them) might not appreciate waiting on you every time you get your pen, paper and pocket calculator out!

OK, we don’t have to go into all that here. Even if you did get your protractor out and calculate the exact slope between you and the hole, it probably wouldn’t be all that helpful. What we really need is a quick way of finding out how far to actually hit the ball compared to what we would expect.

This is where a rangefinder with slope comes in handy. By doing all that geometry you thought you’d never use, the rangefinder can give you an adjusted distance to shoot for.  This adjusted distance is what we need in order to choose a club or know how hard to swing.

The rangefinder with scope will give you two readings: the actual distance to the hole and an adjusted slope distance. That is, a distance to shoot for given the slope that the rangefinder has calculated.

Of course, if you can't see the flag, a rangefinder won't really help!
Of course, if you can’t see the flag, a rangefinder won’t really help!

How Does a Rangefinder Calculate Slope?

Basically, the rangefinder shoots a laser out at a target. When the laser bounces off the target, the delay between its being sent out and returning gives the distances to the flagstick. This is a principle common to all golf laser rangefinder devices, although obviously some do it a lot better than others!

The other calculation that the rangefinder with scope can make is to calculate the angle of return. Unless you are exactly parallel to your target, the returning laser beams will be off a certain number of fractional degrees. The rangefinder is able to use this difference to calculate slope and give you an adjusted distance. This is what saves you doing maths in your head!

All you have to do is play this adjusted distance.

Will a Rangefinder with Slope Improve My Score?

Well, of course, there is no guarantee. But we can certainly say that failing to account for slope will certainly hurt your score. This is because you will likely be under or overhitting the ball. As you get better with adjusting and factoring in slope, you should see some improvement in your overall score. What is clear is that playing without knowing the slope is a whole lot harder.

This also depends on how much the course you play changes in elevation. A relatively flat course will not factor in much slope at all. On very hilly courses, failing to factor for slope could cost you dozens of strokes. I play ever year on a mountain course and from personal experience, my score will blow up if I try to eyeball it.

Does a GPS Calculate Slope?

While GPS might be able to give some indication of your relative elevation, it won’t be able to calculate slope for your specific situation. This doesn’t make it useless, but means that a course with a lot of height changes will reduce its effectiveness quite a bit.

This is because GPS works by using satellites to pinpoint your current location. Then, it calculates your current position against a set of pre-programmed data. Companies have programmed devices with GPS locations throughout various golf courses. The GPS device simply measures the distance between your current location and any of these predetermined points.

So, a GPS device will not be able to calculate for slope, but only estimate your distance to different predetermined locations on the course.

Can I Use Slope in Competitions?

The USGA has issued specific guidelines regarding the use of measuring devices. According to Appendix IV of Rule 14-3 no measuring device that calculates for slope may be used during tournament play

This does not mean, however, that your rangefinder cannot be used at all. The USGA does allow for a Local Rule to permit a “stipulated round” in which measuring devices like rangefinders can be used. But even under these Local Rule situations, rangefinders that calculate for slope are not permitted.

So the long and short of it is, “no,” any rangefinder that calculates for slope is illegal for tournament play. However, dpending on the level of competition, local rules permitting them are actually more and more common and it seems likely that they will be mainstream and accepted in all sorts of rounds over the next year or two.

But the good news is that these rangefinders are perfectly fine during practice, so you can easily use your rangefinder with slope to learn the lay of the land and get a feel for the changes in elevation.

Can I Turn Off Slope on My Rangefinder?

Rangefinder manufacturers are aware of this rule and have made models to compensate. Many of them have the ability to easily switch off the slope function. This might, however, still raise some eyebrows from other players or officials.

Some models have an added faceplate that makes it clear when the slope function is enabled and disabled. You should check your particular model to see just how easy it is to switch the slope calculation off and indicate to others that it has been disabled.

If you  are looking for a rangefinder with or without slope, Nikon makes some of the best products out there for your money.


8 thoughts on “Understanding Slope for Golf Rangefinders”

  1. I just bought a range finder that doesn’t show you the slope. I just wanted to clarify how to read it properly. If the hole is 150 yards away and elevated, I can expect the range finder to show me the true distance (say 160 yards for example), correct? And if that’s the case, I would want to read the hole as the true distance of 160 yards, and most likely use a longer club (if we consider my ball flight and drop angle all the same)?

    • Hi Tyler,
      If your rangefinder doesn’t show slope, it will simply show you the true distance to the flag, regardless of elevation. In your example, if the flag is 150 yards away, the reading on the rangefinder will be 150 yards, regardless of slope/elevation.

      If you take the same reading using a rangefinder that has slope it will take into account changes in elevation and give you a reading telling you how far it is actually playing.

      So in your example, you are 150 yards away and it is a long way up hill, a non-slope version will say 150 yards. A slop version might give you 165 yards because this is how far you effectively need to hit it taking into account to hill.

      Hope that helps, Nick

  2. Good afternoon
    My rangefinder doesn’t give slope reading in yards but does have a angle display. So only gives me the true reading not calculated with the slope ie. I’m on a slightly elevated tee with 150 yards to the flag the small angle display my ready 3% this isn’t giving me a yardage reading for the slope so is that ok ??
    Steven Moss

    • Hi Steven,
      Apologies for the slow reply. It sounds like you are using a rangefinder designed for something else (hunting, maybe?) The reading you are getting is not quite right, but is giving you an idea of how to correct it. For example, 150 yards with your slight downhill might be playing 145 or whatever. You are basically rounding the distance slightly based on the angle.
      You might be fine with this, or not. Perhaps depending on your level and just how precise you want to be with your yardages, for example.

  3. I was hoping to find an actual calculation of slope adjusted. Wouldn’t the flight path, I.e. angle relative to the target ground, make a difference? For a higher loft trajectory, the slope impact uphill is less than a lower lift trajectory. Also not every lie is even, facing uphill or downhill would greatly impact the trajectory as well as club selection. If any of my assumptions are true, then how could there be a slope adjusted distance that applies for a given shot for all lies and lofts?

    • The slope adjustment doesn’t take into account your shot trajectory, simply because that would be impossible! However, all the elements you listed are true for every shot in golf, whatever the lie. A slope calculation will simply give you a modified distance based on whether you are hitting uphill or down.


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