There is often confusion when it comes to shooting uphill and downhill shots on how to adjust for the incline. Do you hold high on uphill shots or low on downhill shots? Vice versa? Or no change at all? The answer may surprise some people.
The key to understanding an arrow’s trajectory on uphill and downhill shots is realizing that gravity only acts perpendicular to the earth’s surface. Thus an arrow is only acted on by gravity for the distance that it travels parallel to the earth, or rather only the horizontal distance. This results in having to aim low for both downhill and uphill shots!
Because the actual distance to the target will always be greater than (or equal to) the horizontal distance to the target, an adjustment must be made when shooting at extreme angles so that the yardage used on the bow sight matches the horizontal distance. By remembering our geometry lessons, we can quickly calculate the amount of yardage that must be “cut” for either an uphill or downhill shot.
A right triangle is formed by the shooter’s height above the target, the actual distance to the target and the horizontal distance to the target. The Pythagorean theorem states that the sum of the squares of the sides of a right triangle is equal to the square of the hypotenuse. By knowing the height the shooter is above the target and the actual distance to the target, the horizontal or the aiming distance can be calculated.
Rather than trying to do the calculations in your head or by hand, the following chart can be used to find the exact yardages:
| Actual Distance to Target | |||||||||||||||
| Height | 10 | 15 | 20 | 25 | 30 | 35 | 40 | 45 | 50 | 55 | 60 | 65 | 70 | 75 | 80 |
| 1 | 9.9 | 15.0 | 20.0 | 25.0 | 30.0 | 35.0 | 40.0 | 45.0 | 50.0 | 55.0 | 60.0 | 65.0 | 70.0 | 75.0 | 80.0 |
| 2 | 9.8 | 14.9 | 19.9 | 24.9 | 29.9 | 34.9 | 39.9 | 45.0 | 50.0 | 55.0 | 60.0 | 65.0 | 70.0 | 75.0 | 80.0 |
| 3 | 9.5 | 14.7 | 19.8 | 24.8 | 29.8 | 34.9 | 39.9 | 44.9 | 49.9 | 54.9 | 59.9 | 64.9 | 69.9 | 74.9 | 79.9 |
| 4 | 9.2 | 14.5 | 19.6 | 24.7 | 29.7 | 34.8 | 39.8 | 44.8 | 49.8 | 54.9 | 59.9 | 64.9 | 69.9 | 74.9 | 79.9 |
| 5 | 8.7 | 14.1 | 19.4 | 24.5 | 29.6 | 34.6 | 39.7 | 44.7 | 49.7 | 54.8 | 59.8 | 64.8 | 69.8 | 74.8 | 79.8 |
| 6 | 8.0 | 13.7 | 19.1 | 24.3 | 29.4 | 34.5 | 39.5 | 44.6 | 49.6 | 54.7 | 59.7 | 64.7 | 69.7 | 74.8 | 79.8 |
| 7 | 7.1 | 13.3 | 18.7 | 24.0 | 29.2 | 34.3 | 39.4 | 44.5 | 49.5 | 54.6 | 59.6 | 64.6 | 69.6 | 74.7 | 79.7 |
| 8 | 6.0 | 12.7 | 18.3 | 23.7 | 28.9 | 34.1 | 39.2 | 44.3 | 49.4 | 54.4 | 59.5 | 64.5 | 69.5 | 74.6 | 79.6 |
| 9 | 4.4 | 12.0 | 17.9 | 23.3 | 28.6 | 33.8 | 39.0 | 44.1 | 49.2 | 54.3 | 59.3 | 64.4 | 69.4 | 74.5 | 79.5 |
| 10 | 11.2 | 17.3 | 22.9 | 28.3 | 33.5 | 38.7 | 43.9 | 49.0 | 54.1 | 59.2 | 64.2 | 69.3 | 74.3 | 79.4 | |
| 11 | 10.2 | 16.7 | 22.4 | 27.9 | 33.2 | 38.5 | 43.6 | 48.8 | 53.9 | 59.0 | 64.1 | 69.1 | 74.2 | 79.2 | |
| 12 | 9.0 | 16.0 | 21.9 | 27.5 | 32.9 | 38.2 | 43.4 | 48.5 | 53.7 | 58.8 | 63.9 | 69.0 | 74.0 | 79.1 | |
| 13 | 7.5 | 15.2 | 21.4 | 27.0 | 32.5 | 37.8 | 43.1 | 48.3 | 53.4 | 58.6 | 63.7 | 68.8 | 73.9 | 78.9 | |
| 14 | 5.4 | 14.3 | 20.7 | 26.5 | 32.1 | 37.5 | 42.8 | 48.0 | 53.2 | 58.3 | 63.5 | 68.6 | 73.7 | 78.8 | |
| 15 | 13.2 | 20.0 | 26.0 | 31.6 | 37.1 | 42.4 | 47.7 | 52.9 | 58.1 | 63.2 | 68.4 | 73.5 | 78.6 | ||
| 16 | 12.0 | 19.2 | 25.4 | 31.1 | 36.7 | 42.1 | 47.4 | 52.6 | 57.8 | 63.0 | 68.1 | 73.3 | 78.4 | ||
| 17 | 10.5 | 18.3 | 24.7 | 30.6 | 36.2 | 41.7 | 47.0 | 52.3 | 57.5 | 62.7 | 67.9 | 73.0 | 78.2 | ||
| 18 | 8.7 | 17.3 | 24.0 | 30.0 | 35.7 | 41.2 | 46.6 | 52.0 | 57.2 | 62.5 | 67.6 | 72.8 | 77.9 | ||
| 19 | 6.2 | 16.2 | 23.2 | 29.4 | 35.2 | 40.8 | 46.2 | 51.6 | 56.9 | 62.2 | 67.4 | 72.6 | 77.7 | ||
| 20 | 15.0 | 22.4 | 28.7 | 34.6 | 40.3 | 45.8 | 51.2 | 56.6 | 61.8 | 67.1 | 72.3 | 77.5 | |||
| 21 | 13.6 | 21.4 | 28.0 | 34.0 | 39.8 | 45.4 | 50.8 | 56.2 | 61.5 | 66.8 | 72.0 | 77.2 | |||
| 22 | 11.9 | 20.4 | 27.2 | 33.4 | 39.3 | 44.9 | 50.4 | 55.8 | 61.2 | 66.5 | 71.7 | 76.9 | |||
| 23 | 9.8 | 19.3 | 26.4 | 32.7 | 38.7 | 44.4 | 50.0 | 55.4 | 60.8 | 66.1 | 71.4 | 76.6 | |||
| 24 | 7.0 | 18.0 | 25.5 | 32.0 | 38.1 | 43.9 | 49.5 | 55.0 | 60.4 | 65.8 | 71.1 | 76.3 | |||
| 25 | 16.6 | 24.5 | 31.2 | 37.4 | 43.3 | 49.0 | 54.5 | 60.0 | 65.4 | 70.7 | 76.0 | ||||
| 26 | 15.0 | 23.4 | 30.4 | 36.7 | 42.7 | 48.5 | 54.1 | 59.6 | 65.0 | 70.3 | 75.7 | ||||
| 27 | 13.1 | 22.3 | 29.5 | 36.0 | 42.1 | 47.9 | 53.6 | 59.1 | 64.6 | 70.0 | 75.3 | ||||
| 28 | 10.8 | 21.0 | 28.6 | 35.2 | 41.4 | 47.3 | 53.1 | 58.7 | 64.2 | 69.6 | 74.9 | ||||
| 29 | 7.7 | 19.6 | 27.5 | 34.4 | 40.7 | 46.7 | 52.5 | 58.2 | 63.7 | 69.2 | 74.6 | ||||
| 30 | 18.0 | 26.5 | 33.5 | 40.0 | 46.1 | 52.0 | 57.7 | 63.2 | 68.7 | 74.2 | |||||
| All Measurements in Yards | |||||||||||||||
(download a .pdf of the chart here)
You may notice that there is not a lot of difference in most cases; only when the height above the target is extreme or approaching that of the horizontal distance does cutting yardage become an issue. However, the difference is there and can affect the impact site of an arrow, especially when shooting at the 12 ring on a 3D target or the vitals of a animal.
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{ 5 comments… read them below or add one }
Are the numbers in the HEIGHT column represented in feet or yards? I could not imagine being 30 YARDS above a target… Thank you…
Craig, the numbers are all in yards. While you may not find it normal to be 30 yards above a target, it is possible (though hopefully not from a treestand!) Especially when hunting out west in the mountains, steep slopes are often encountered and can present such situations. Not to mention that at many of the 3D tournaments long shots with large elevation changes are regular occurrences to really test your ability.
This sounds logical, but I have an issue. I need to drop point of aim by 6″ when shooting a target levated 6 yards and the total distance to the target is 20 yards. But If I shot on the ground I can 19.1 yards and 20 yards with no measurealbe difference. 6″ below my sight picture at 20 yards is more like 16 yards on the ground.
So, I think the angle of the gravity’s pull to the line of site must alos have an impact.
Russ,
I can fully guarantee you that the only effect that gravity has is on the horizontal path. What often happens with shooters is that they feel that there is more of an impact on elevated targets, but in reality they are usually doing something to change their shooting form and that has a larger effect on the impact position of the arrow. When shooting at elevated targets or from an elevated position, it is critical to bend at the waist and keep your anchor point identical, otherwise the vertical impact point will be affected.
I’m not saying this is the case with you, but I do know that gravity’s effect on projectiles is well known and understood.
I have seen the effect on arrow impact with downhill shots as I do most of my hunting in steep canyon lands. I shot a buck at 37 yards. My rangefinder said to shoot for 25 yards, but I thought that was a little off, so I shot for 30. The result was a high lung shot that resulted in longer suffering than should have been. He did not go far as I did not push him, but it took about 5 minutes where as a good center lung shot only takes about 30 seconds on average. I talk more about it at my website http://www.bestforhunting.com