Why do I need twice the pitch length?

When leading a climb, the rope must reach from the belayer to the leader at the top of the pitch, and then back down if lowering off. This means you need at least twice the pitch height plus a safety margin for anchoring and knots.

What is the standard climbing rope length?

The most common single rope lengths are 60m and 70m. A 60m rope covers most single-pitch sport routes and many multi-pitch routes. A 70m rope provides extra margin and is becoming more popular as sport routes get longer.

When should I use half ropes?

Half ropes (also called double ropes) are used on trad multi-pitch climbs where the route wanders, and for long rappels. You clip each rope to alternating pieces of protection to reduce rope drag and can join them for rappels up to their full combined length.

How much rope length do knots use?

A figure-eight knot uses approximately 30-40cm of rope. When tied into both ends with knots at belay anchors, you lose roughly 1-2m of usable rope length. The 5m safety margin in this calculator accounts for this.

CampCalcs

Rope Length Calculator

Calculate the minimum rope length needed for your climb and rappel based on pitch length and descent requirements.

Longest Pitch

Height of the longest pitch

Number of Pitches

Route Length

Total route vertical height

Rope Type

Rappel required

Will you need to rappel down?

How We Calculate This

This calculator determines the minimum rope length based on your longest pitch and rappel requirements.

Minimum rope formula

Minimum rope = (Longest pitch x 2) + Safety margin (5m)

Rappel calculation

Rappel rope needed = Rappel height x 2 + 3m (for anchor and knots)

The calculator recommends the nearest standard rope length (30m, 40m, 50m, 60m, 70m, or 80m) that meets your minimum requirements.

Frequently Asked Questions

Related Calculators

Belay Calculator

Calculate belay forces, friction and holding power for different belay devices.

Knot Strength Calculator

Compare knot types and calculate retained rope strength after tying.

Fall Factor Calculator

Calculate fall factor, impact force and energy from fall distance and rope out.

Anchor Calculator

Calculate load distribution across multiple anchor points at different angles.

Rack Calculator

Build a climbing rack list based on route grade, length and crack sizes.

Last updated: February 2026

All calculations are estimates. Always verify conditions and use proper safety equipment outdoors.