Ice climbing grades

Technical Rating:
These numbers apply to WaterIce - WI and AlpineIce - AI.

These are actually "commitment" ratings, and somehow such squishy qualities such as "scariness" are factored into the rating. Suffice it to say that range of difficulty within each rating is broad. The technical grade describes the hardest pitch of the route. In general, the technical difficulty of a climb is based on the usual conditions encountered. Since the technical difficulty of a climb depends directly from the quality of the ice, be aware that conditions outside the average will affect the rating.

1 Walking up with crampons. No tools required.
2 A pitch of 60º-70º ice, reasonably consistent, with few short steep steps. Only one tool is needed. Good protection and belays.
3 Sustained 70º-80º ice, usually thick and solid. May contain short, steep sections, but will have good resting places and offer good protection and belays.
4 Sustained 75º-85º ice, separated by good belays, or a less steep pitch with significative vertical sections. Generally good quality ice, offering satisfactory protection.
5 A noticeably more strenuous pitch of good but steep (85º-90º) ice.
6 A very steep, strenuous pitch with few stances for rest. The ice may not be of top quality and protection may be poor. A high level of skill and strength is required.
7 An overhanging, strenuous pitch with few resting places and often

Grade Rating:
I A short climb with a short approach and easy descent. Time required is an hour, or two.
II A 1 or 2 pitch climb with a short approach and easy descent by rappeling, or downclimbing. Time required is a few hours.
III A multi-pitch route at a low elevation which may take several hours, or a route with a long approach that requires good winter travel skills, or a route subject to occasional winter hazards. The descent is often by rappeling. Time required is half a day.
IV A multi-pitch route at higher elevations, or a remote route which requires mountaineering and winter travel skills. May be subject to objective hazards (i.e. avalanche, or rockfall). The descent may be difficult, and involve rappeling. Time required is a most of a day.
V A long climb on a high mountain face that requires significant competence as well as commitment. The climb is subject to objective hazards in addition to bad weather. The approach and descent may be long and difficult. Time required is a long day, or two.
VI A long, multi-pitch route on a high alpine face. The climb may include winter alpine climbing logistical problems in addition to severe objective hazards ( i.e. avalanche, falling seracs, high elevation and remoteness). Time required is many days.

Mixed climbing:
Over the last couple of years there has been a dramatic rise in ice-climbing standards; ice falls are being freed and the scale is shifting upwards rapidly.
This has been brought about by the fact that previously unclimbed bands of rock are being overcome with the use of ice-axe and crampons, thereby linking various sections of ice. This is known as dry tooling and it has invariably brought with it a new grading system.
The letter M indicates that the route is mixed (ie. ice and rock), and this is followed by a number which indicates the technical difficulties.
At present the open-ended scale starts at M1 and finishes at M13.

These routes require considerable dry tooling (modern ice tools used on bare rock) and are climbed in crampons; actual ice is optional but some ice is usually involved.

M1-3Easy. Low angle; usually no tools.
M4Slabby to vertical with some technical dry tooling.
M5Some sustained vertical dry tooling.
M6Vertical to overhanging with difficult dry tooling.
M7Overhanging; powerful and technical dry tooling; less than 10m of hard climbing.
M8Some nearly horizontal overhangs requiring very powerful and technical dry tooling; bouldery or longer cruxes than M7.
M9Either continuously vertical or slightly overhanging with marginal or technical holds, or a juggy roof of 2 to 3 body lengths.
M10At least 10 meters of horizontal rock or 30 meters of overhanging dry tooling with powerful moves and no rests.
M11A ropelength of overhanging gymnastic climbing, or up to 15 meters of roof.
M12M11 with bouldery, dynamic moves and tenuous technical holds.