Frequently Asked Questions

The Hammock Hang Calculator FAQ

How do I use the calculator?

The purpose of the Hammock Hang Calculator is to help you take the guesswork out of hanging your hammock to get a perfect setup every time.  However, there are a few things you need to know about your hammock before venturing out into the field!

The first is the length of your hammock itself.  The best thing to do is to measure your hammock when it is spread out flat on the floor - its best to measure the actual length of your hammock as it will sometimes vary from what the manufacturer's stated length.

The second bit of information you need is whether or not you are using a structural ridgeline.  Some hammocks come with built in ridgelines and others don't.  You can very easily add a ridgeline to your hammock - once you get your hammock dialed in, a structural ridgeline will make it much easier for you to get a consistent, comfortable hang every time out.  If you already have a ridgeline, measure how long it is.  If not, be sure to enter a value of "0" (zero) in the field for the ridgeline length.

The last bit of information is your preferred sit height.  When you are sitting up in your hammock and using it as a chair, the preferred sit height is the distance from your bottom to the ground.  You can experiment with different heights to see what you are comfortable with, most folks start with a value of 18" (46 cm).

With this information handy, you are now ready to venture out and find your perfect hammock setup by using the Hammock Hang Calculator!

Once you find a good looking spot with some sturdy trees nearby, be sure to make sure and check that there are no dead branches hanging overhead.

Next, measure or estimate the distance between the two trees and keep the other information you have collected about your hammock handy.

Start up the Hammock Hang Calculator app.  You will notice on the right hand side of the screen you can pull out a tab that lets you enter your information into the calculator.  Go ahead and enter all the information into the appropriate fields.  You can switch between metric and english units by using the slider at the top of the input screen.

If you enter your weight, the calculator will also determine how much force is being applied to the trees and along your suspension.  This information is there to help you make sure that you are picking a suitable tree that can withstand the amount of force required to hold you up and that you have an adequate suspension system in place.

Lastly, the hang angle represents the desired angle between the horizon and your suspension system where it connects to the tree.  Most hammockers stick with the default value of 30°.  You may want to experiment with a few different values here once you are more comfortable with  your hammock, but pay close attention to how much force you are putting on the trees and your suspension.

Once you have entered all the information into the Hammock Hang Calculator, click the "Done" button (or swipe right) and the input tab will close.  Now you are ready to get the perfect hang!

The first thing you want to do is to attach your suspension to the tree.  Look at the value for Hang Point in the calculator and hang your suspension at that height off the ground on both trees.  The next thing you will want to do is to adjust your suspension length to match what is shown in the calculator.  Depending on your suspension system, it might take a few tries to make sure you get things adjusted to the specified length.

Once you have attached your hammock and adjusted the suspension length, take a few steps back to take a good look at your setup.  You should see your hammock hanging perfectly centered between the two trees, with the angle of the suspension matching what you entered into the Hammock Hang Calculator.  Note the values for shear force and cord tension, and ensure that both the trees you have selected and your suspension system can handle the projected load.  If anything doesn't look right, go back and make sure you have entered your information correctly and that you are using the right units for each input field.

If everything looks good, walk up to your hammock and ease into it slowly to make sure that the suspension is secure.  When you sit in the hammock, you should find yourself sitting at your preferred sit height.

If you don't have a structural ridgeline, you should also note that the Hammock Hang Calculator has calculated what it would be given the current setup.  You can use this as a starting point if you choose to add one in the future.  Some users find that small adjustments in the structural ridgeline length can make a big difference in how your hammock hangs and how flat of a lay you get, so you may want to see what feels most comfortable.

If everything is secure, lay back in your hammock and enjoy the perfect hang!

What is “Suspension Length”?

Suspension Length is the distance along the cord or webbing from which the hammock hangs, from the end of the hammock to the anchor (i.e., tree or post).

What is “Cord Tension”?

Cord Tension is the force exerted on the anchor point in line with the suspension. Tension is dependent on the combined weight of the hammock occupant, the hammock itself, and any gear attached to the hammock and on the Hang Angle.

What is “Shear Force”?

Shear Force is the force exerted in a horizontal direction away from the suspension anchor point. As with cord tension, it is dependent on hammock, occupant, and gear weight and on Hang Angle.

What is “Weight in hammock”?

Weight in Hammock includes the weight of the hammock, its occupant, and any gear attached to the hammock.

What is the “Distance between anchors”?

Distance Between Anchors is the straight-line horizontal distance between the two anchor points.

What is the “Hang Angle”?

The Hang Angle is the angle between the horizontal and the suspension cord or webbing, when the hammock is occupied. The hang angle may be increased by lengthening the suspension length, or decreased by shortening the suspension length. Finding the right suspension length (and hence hang angle) is a critical part of hanging the hammock. Thirty degrees is often a target angle, as the cord tension is then just the weight of the hammock's occupant, well within the safe working load on most materials used for the hammock suspension.

What is “Preferred sit height”?

Preferred sit height is the distance from the ground to the bottom of the center of the hammock when the occupant is sitting in the center. Think of it as the height of the seat of a chair.

What is Ridgeline Length?

Ridgeline Length is the end-to-end length of an optional ridgeline, or distance between hammock ends if there is no ridgeline, when the hammock is occupied. In the presence of a ridgeline, this measure assumes it is attached at or very close to the ends of the hammock.

What is Hammock Length?

Hammock Length is the length of the hammock, laid flat out on the ground, typically between 9 and 11 feet (i.e., 108 and 132 inches).