Hammock Hang Calculator

Enter Calculation

Distance between anchors (ft)

Hang angle (degrees)

Body weight (lb)

Desired sit height off ground (ft)

Results

Anchor Height (attach strap above ground)

4.96

feet

Hammock sag (center drop below anchors)	3.46 ft
Tension per anchor point	180 lb

What Is the Hammock Hang Calculator?

Getting a comfortable, safe hammock hang is all about geometry. This calculator turns three things you can measure — the distance between your two anchors, the hang angle of the straps, and your body weight — into the numbers you actually need: how high to attach the straps, how much the hammock will sag in the middle, and how much force pulls on each anchor.

How to Use It

Measure the distance between your two trees or posts and enter it in feet. Pick a hang angle — most hammock campers aim for the widely recommended 30° strap angle, which balances comfort and tension. Enter your body weight and the height off the ground you want to sit at (around 1.5 ft is typical for easy entry). The calculator returns the anchor height to attach your straps, the resulting center sag, and the tension per anchor.

The Formula Explained

The hammock forms a shallow V. With a strap angle \(\theta\) measured from horizontal, the center drops by $$\text{Sag} = \frac{\text{Distance (ft)}}{2}\tan\theta$$ below the anchor points. To keep your seat at the desired height, the anchors must sit at $$H = \text{Sag} + \text{Sit Height (ft)}$$ above the ground. The suspension tension follows from statics: each line supports half your weight vertically, so $$T = \frac{\text{Weight (lb)}}{2\,\sin\theta}$$ Shallower angles (smaller \(\theta\)) feel flatter but multiply tension dramatically.

Strap tension T rises sharply as the hang angle theta gets shallower.

Key measurements: distance d, hang angle theta, anchor height and center sit height.

Worked Example

Anchors 12 ft apart, 30° hang angle, 180 lb body, 1.5 ft sit height. $$\text{Sag} = \frac{12}{2}\times \tan 30° = 6 \times 0.5774 = 3.46\ \text{ft}$$ $$H = 3.46 + 1.5 = 4.96\ \text{ft}$$ $$T = \frac{180}{2} \div \sin 30° = \frac{90}{0.5} = 180\ \text{lb per anchor}$$

FAQ

Why is 30° recommended? It gives a comfortable lie-flat sag without producing excessive tension on your gear and trees.

What happens at small angles? A tight, near-horizontal hang (e.g. \(10°\)) can multiply tension to several times body weight, stressing straps and anchors.

Is the height exact? It's a close geometric estimate; fabric stretch and ridgeline setup may require small adjustments in the field.