Tarp Pitch & Cordage Planner

How to use the tarp planner

1. Choose your tarp size: 2 × 3, 3 × 3, 3 × 4 or 4 × 4 m.
2. Select the expected weather: fair, rain, wind and rain, or cold with a campfire.
3. Choose whether you sleep on the ground or in a hammock, and for 1 or 2 people.
4. Enter the distance between the trees for your ridgeline.

How it is calculated

The pitch is chosen by weather. On the ground: fair weather gives an open lean-to (35°), cold weather a lean-to facing a long fire (45°), rain a classic A-frame (50°) and wind with rain a low A-frame (38°) – or a plow point if the tarp is narrower than 3 m. Over a hammock you get a diamond in fair weather, an A-frame in rain and a steep storm mode with closed ends in wind or cold.

The geometry is simple trigonometry. For ridge pitches each half of the tarp slopes down at the pitch angle: ridge height = half the width × sin(angle), covered width = width × cos(angle). For a lean-to the whole width is tilted. Over a hammock the ridge is set to at least 1.8 m. The planner checks whether the covered floor fits you: about 0.8 m wide for one person, 1.5 m for two, and 2.2 m long (3 m for a hammock).

Cord: ridgeline = tree distance + 2 × 1.5 m for wraps and knots, plus 2 m per guyline (4 for a lean-to, 6 for ridge pitches), plus 10 % reserve.

Practical tips

• Point the low or narrow end into the wind.
• Look up before pitching: never camp under dead branches.
• Re-tension nylon tarps after dark – they stretch when wet and cold.
• Carry a few metres more cord than calculated; trees are rarely where you want them.