See what fits under your tarp.
An ideal A-frame: straight ridge, equal slopes, fabric edges at ground level. Sag, stretch, seams, doors and sloping ground are omitted. Stake holding depends on soil and setup; no universal stake angle is prescribed. Wind bearings are a plan view, not a load or thermal prediction. Keep stoves and flames outside shelters.
Model details & unit conventions ↗Work out A-frame tarp floor width, wall angle and usable headroom from ridge height, with a table for a 3 m tarp and the formulas behind it.
Choose tarp size for camping: floor width, wall angle, sleeping length and fabric area for 2×3, 3×3 and 3×4 m tarps, with the arithmetic shown.
Work out tarp guyline length from ridge height and stake distance, then add a ridgeline allowance for tree spacing, trunk wraps and knots.
Pitch a tarp for wind by lowering the ridge, turning an open end away from the wind and keeping guylines tight, with the cost in headroom.
How to choose a campsite: check rules, overhead hazards, drainage and sleeping ground, then use sunrise bearing to place the open end of a tarp.
Find sunrise and sunset bearings by season and latitude, with a table from 0° to 60° N, and set a tarp’s open end for morning sun or shade.
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