Bouldering: short climbs, no rope.

What bouldering is

The BMC (British Mountaineering Council) defines bouldering as climbing at low height on small rocks, boulders or indoor walls. The climbs are called boulder problems, and padded mats are commonly placed underneath. Wikipedia's overview adds that bouldering is done without ropes, on short boulders or small outcrops.

With no rope, there is no belayer in the roped-climbing sense. The padded mats the BMC mentions are often called crash pads, and the crash pads page explains what they are and what is published about them.

Highballs

Some boulder problems are tall. The BMC describes highballing as the point where bouldering meets soloing: a tall boulder problem or a short route, usually climbed with pads and spotters, and it calls highballing high-risk. Wikipedia also uses "highball" for very tall problems.

Bouldering grades

Bouldering has its own grade scales, separate from route grades. This page covers the V scale and the Font scale. The full picture, including every other scale, is on the grading systems page.

The V scale

Wikipedia credits the V scale to John "Verm" Sherman, who set it out in his 1991 guidebook to Hueco Tanks; the V comes from his nickname. The American Alpine Club's review of the 1996 second edition of that guide notes that the V rating system is explained in the book.

A technical paper by the Italian Alpine Club (CAI), written by G. Mandelli and A. Angriman and hosted by the UIAA, describes the V scale as starting at V0 and reaching somewhere between V14 and V15 at the time it was written. The paper is undated, so that top end is out of date. Wikipedia gives the top V grade stated in 2026 as V17, for the problem Burden of Dreams, which is graded 9A on the Font scale.

The Font scale

The CAI paper calls Fontainebleau the cradle of bouldering in Europe. The Font scale named after it uses numbers with letters (6a, 6b and so on). The paper points out that these do not mean the same thing as route grades written with the same symbols, so a Font 6a boulder problem is not the same difficulty as a French 6a route. The gear maker Mammut, in a July 2025 explainer, says Font grades are rated somewhat easier for traverses than for boulder problems of the same number; that is a maker's description.

Older and specialist scales

• Wikipedia dates John Gill's three-step B scale (B1 to B3) to 1958. We found this in Wikipedia only, so it is unconfirmed.
• The CAI paper describes a separate grade for psicobloc (deep-water soloing) that combines an adjectival grade with a Font technical grade.

How the V and Font scales line up

Published charts do not agree on where the two scales meet at the easy end. Mountain Project's chart pairs V0 with Font 4, while Mammut (2025) pairs V0 with roughly Font 5c. The grade comparison tables page shows each chart's pairings side by side.

Bouldering indoors

Indoor bouldering walls are covered by their own part of the European standard for artificial climbing structures. Standards catalogue pages list EN 12572 in three parts: Part 1 for structures with protection points, Part 2 for bouldering walls and Part 3 for holds. Part 1 is dated 2017, and the Estonian Centre for Standardisation's catalogue lists the current editions of Parts 2 and 3 as EN 12572-2:2017 and EN 12572-3:2017.

In the UK, bouldering-only walls make up a large share of the walls the ABC surveyed. The Association of British Climbing Walls (ABC), in its fifth climbing wall survey published on 6 November 2025, reported that 62% of walls opened in the previous four years offer bouldering only, and that 46% of all walls surveyed are bouldering only. Those are the ABC's figures for its survey, not a census of every wall.

The ABC's Code of Practice, the minimum standard it sets for climbing walls, says novice boulderers should have a safety induction or be supervised. The climbing gyms page covers what the ABC and the US Climbing Wall Association publish for wall operators.

Bouldering in competition

Bouldering is one of World Climbing's three competition disciplines, alongside lead and speed. World Climbing was called the IFSC (International Federation of Sport Climbing) until it rebranded on 10 December 2025.