V18 sits one grade above the current confirmed maximum bouldering grade in the world (V17, equivalent to Font 9A). As of 2026, no boulder problem has been universally accepted as V18. The grade is theoretical: the bouldering grade scale is open-ended, and V18 remains a benchmark climbers might one day reach.
A handful of unrepeated V17 problems exist worldwide, and a few problems have been suggested as V17/V18 by their first ascensionists — but consensus only emerges after multiple repeats. The most influential top-end boulderers (Daniel Woods, Nalle Hukkataival, Shawn Raboutou, Ryuichi Murai, Aidan Roberts) have all proposed V17s; some have suggested specific problems may eventually be confirmed as V18.
For context: V17 is the equivalent of an Olympic-medal performance level in pure power-and-finger-strength terms. Reaching V18 would require multiple specific physical adaptations — stronger fingers, better movement, longer and more progressive training cycles than have ever been completed — and conditions favourable enough to perform on a single rare day. The grade is the bouldering equivalent of a sub-2-hour marathon: theoretically possible, currently unproven.