Free tool
Tree Height & Climbing Rope Length Calculator
Measure tree height from the ground with a distance and angle, then find how much climbing rope you need for a doubled (MRS) or single-line (SRS) climb.
Climbing rope and throw line
Measuring a tree from the ground
Pace or tape a distance from the trunk on level ground, then sight the top of the tree with a clinometer or phone level app. Height is your distance multiplied by the tangent of the angle, plus your eye height. If you have no clinometer, the stick method works: hold a stick at arm’s length so its length above your hand equals your arm length, then back up until it covers the tree from base to top. Your distance from the trunk then roughly equals tree height.
How much rope do I need?
A doubled moving-rope climb needs at least twice the height of your tie-in point plus enough tail to tie off and work, while a stationary rope needs the height plus the tail. The calculator adds a working margin and suggests the next common rope length up, because running out of rope on the way down is not an option. Always tie a stopper knot in the tail.
Common questions
How long should an arborist climbing rope be?
150 feet covers most moving-rope climbs to about 60 feet. Taller trees or SRS work from a basal anchor often call for 200 feet or more.
Is the stick method accurate?
It is usually within 10 to 15 percent on level ground, which is good enough for choosing rope length, but not for felling distances, where you should add a generous safety margin.