The British grading system for traditional climbs has two parts: the adjectival grade and the technical grade. (Sport climbing in Britain uses the French grading system, often prefixed with the letter “F”.)
The adjectival grade attempts to assess the overall difficulty of the climb taking into account all factors, for a climber leading the route on sight in traditional style. In the early 20th century it ran Easy, Moderate, Difficult, but increasing standards have several times lead to extra grades being added at the top. The adjectival grades are as follows:

• Easy (rarely used)
• Moderate (M)
• Difficult (D, or ‘Diff’)
• Very Difficult (VD, or ‘VDiff’)
• Hard Very Difficult (HVD)
• Severe (S)
• Hard Severe(HS)
• Very Severe (VS)
• Hard Very Severe (HVS)
‚Ä¢ Extremely Severe (E1, E2, E3, …)
• XS is used for climbs that are on loose or crumbling rock that are seldom repeated after the first ascent

The Extremely Severe grade is subdivided in an open-ended fashion into E1 (easiest) then E2, E3 and so on. As of 2006 the hardest climb is graded E11, but many climbers consider such high grades provisional as the climbs have not yet been climbed by anyone on sight. The hardest confirmed grade is E9.

Some guidebooks make finer distinctions by adding the prefix “Mild” or “Hard” (thus, Hard Very Difficult and Mild Severe lie between Very Difficult and Severe).
The technical grade attempts to assess only the technical climbing difficulty of the hardest move or moves on the route without regard to the danger of the move or the stamina required if there are several such moves in a row. Technical grades are open-ended, starting at 1 and subdivided into “a”, “b” and “c”, but you are unlikely to see any mention of them below 4a. The hardest recorded climbs are around 7b.

Usually the technical grade increases with the adjectival grade but a hard technical move very near the ground (that is, notionally safe) may not raise the standard of the adjectival grade very much. VS 4c might be a typical grade for a route. VS 4a would usually indicate very poor protection (easy moves, but no gear), VS 5b would usually indicate the crux move was the first move or very well protected. On multi-pitch routes it is usual to give the overall climb an adjectival grade and each pitch a separate technical grade (such as HS 4b, 4a).

Grade Comparison Chart