SAC hiking scale T1–T6 explained

The six grades

The names next to each grade (hiking, mountain hiking, alpine hiking…) come from the earlier edition. The 2023 revision dropped them and refers to the grades only as T1 to T6, but they remain in common use — in OpenStreetMap, for example.

T1 Hiking · Wandern

Terrain: Well-built path. Any exposed spots are very well secured. With normal behaviour, the risk of a fall can largely be ruled out.

Requirements: No specific requirements. Finding the way is unproblematic, usually possible even without a map.

T2 Mountain hiking · Bergwandern

Terrain: Path with a continuous line. Terrain steep in places. The risk of a fall cannot be ruled out.

Requirements: Basic sure-footedness. Basic navigation skills.

T3 Demanding mountain hiking · Anspruchsvolles Bergwandern

Terrain: Path not necessarily visible throughout. Steep terrain. Exposed spots may be secured with ropes or chains. Scree and easy broken rock. You may need your hands for balance. Some exposed spots with a possible risk of falling.

Requirements: Sure-footedness. Average navigation skills. Basic alpine experience.

T4 Alpine hiking · Alpinwandern

Terrain: Traces of a path, often pathless. Rough, steep terrain. Isolated easy climbing moves (UIAA grade I). Boulder fields. Steep grass slopes and broken rock. Easy snowfields. Glacier passages, mostly marked. Exposed spots with a risk of falling.

Requirements: Familiarity with exposed passages. Good sure-footedness. Good navigation skills. Alpine experience and a basic ability to assess terrain. Basic knowledge of technical alpine equipment (rope, ice axe, crampons). If the weather breaks, retreat can be difficult.

T5 Demanding alpine hiking · Anspruchsvolles Alpinwandern

Terrain: Traces of a path, often pathless. Rough, steep terrain. Easy climbing passages (UIAA grade I–II). Demanding boulder fields. Very steep grass slopes and broken rock. Steep snowfields. Glacier passages, sometimes marked. Exposed terrain with a risk of falling over longer stretches.

Requirements: Familiarity with exposed terrain. Very good sure-footedness. Very good navigation skills and a feel for route-finding. In-depth alpine experience and reliable terrain assessment. Good knowledge of technical alpine equipment. If the weather breaks, retreat can be very difficult.

T6 Difficult alpine hiking · Schwieriges Alpinwandern

Terrain: Mostly pathless. Markedly steep terrain. Longer climbing sections (UIAA grade II). Tricky boulder fields. Extremely steep grass slopes and broken rock. Tricky snowfields. Glacier passages. Very exposed terrain with a heightened risk of falling over longer stretches.

Requirements: Familiarity with very exposed terrain. Excellent sure-footedness. Very good navigation skills and a feel for route-finding. Mature alpine experience and very reliable terrain assessment. Expert handling of technical alpine equipment. If the weather breaks, retreat can be very difficult.

How to read a grade

Graded for good conditions: A grade assumes favourable conditions: good weather and visibility, dry ground, normal water levels in streams and no snow. Rain, fog, snow or ice make a route harder than its grade says.
The hardest passage decides: A route is graded by its most delicate passages, not by its average. A walk that follows an easy path almost all the way is still an alpine hike if a short section crosses steep, exposed ground. Nor does a route have to match every criterion listed for its grade.
Plus and minus: Grades can be refined with + and −, for example T3, T3+, T4−, T4.
What the grade does not tell you: The scale rates technical difficulty only. It says nothing about length, ascent or physical effort, nor about seriousness — how far you are from shelter if the weather turns. A long T2 can be a far more tiring day than a short T4.
Altitude is not part of it: The grade describes the ground, not the elevation. A broad, well-built path high in the mountains can be T1, and a path across sea cliffs can be T4.
Footwear: Since 2023 the scale no longer prescribes equipment for each grade. SAC’s general rule: the higher the difficulty, the poorer the path and the rougher and less stable the ground, the more advisable sturdy high-cut mountain boots with a torsionally stiff sole become.
Glacier passages: Where the definitions mention glaciers, they mean passages that in summer, under normal conditions, are free of snow to the point where any crevasses can be clearly seen and safely avoided — as on some high hut approaches. Mountaineering equipment is then unnecessary. In unfavourable conditions a rope, crampons or an ice axe may be advisable or even essential.

T5 and T6 are not “just hiking”

On a T5 or T6 route you can rarely or never be protected with a rope, so the terrain has to be mastered completely — very steep grass slopes, pathless broken rock of poor quality, very exposed ridges. That takes solid technique and a steady head.

For that reason SAC notes that alpine hiking at T5/T6 is generally considerably more demanding than an easy mountaineering route graded L (leicht, the lowest grade of SAC’s mountaineering scale) or a roped climb at UIAA grade II. The two scales cannot be compared directly, but a T6 route can make demands comparable to some mountaineering routes graded WS (wenig schwierig), in isolated cases even ZS−.

SAC grades and Swiss trail markings

Switzerland signposts its trails in three categories. They are related to the T grades but not identical to them — since 2023 SAC describes the ranges as overlapping rather than fixed:

Yellow — hiking trails (Wanderweg), mostly in the T1–T2 range.
White-red-white — mountain trails (Bergwanderweg), mostly T2–T3.
White-blue-white — alpine trails (Alpinwanderweg), mostly T4–T5.

In practice, SAC adds, there are frequent deviations both downwards and upwards. The colour of the marking is a first hint, not a substitute for the grade of the specific route.

The SAC scale in OpenStreetMap and TrailPack

OpenStreetMap records trail difficulty in the sac_scale tag, and TrailPack’s route planner reads it from there. Each leg of a planned route is coloured by the hardest grade it contains, and the route as a whole shows the highest grade found anywhere along it.

Grade	OpenStreetMap value
T1	`sac_scale=hiking`
T2	`sac_scale=mountain_hiking`
T3	`sac_scale=demanding_mountain_hiking`
T4	`sac_scale=alpine_hiking`
T5	`sac_scale=demanding_alpine_hiking`
T6	`sac_scale=difficult_alpine_hiking`

The tag is filled in by volunteer mappers and is based on an earlier edition of the SAC scale. It is a judgement call: two mappers may differ by a grade on the same path. The scale was devised for the Alps but is now applied to trails everywhere.

Many paths carry no grade at all. A leg without a T grade does not mean the path is easy — in most cases nobody has recorded a grade yet.

Plan a route and see its grades

Frequently asked questions

What does T3 mean?

T3 is demanding mountain hiking: the path is not necessarily visible throughout, the terrain is steep, exposed spots may be secured with ropes or chains, and you may need your hands for balance. SAC expects sure-footedness, average navigation skills and basic alpine experience.

Which grades are suitable without mountain experience?

By SAC’s definitions, T1 has no specific requirements and T2 asks only for basic sure-footedness and basic navigation skills. T3 already expects basic alpine experience, and from T4 upwards alpine experience, familiarity with exposed ground and the ability to assess terrain are part of the definition.

Does a higher grade mean a longer or more strenuous route?

No. The grade rates technical difficulty only — the hardest ground you will meet. Length, ascent and effort have to be judged separately.

Is every white-blue-white trail T4 or harder?

Not necessarily. Alpine trails marked white-blue-white are mostly in the T4–T5 range, but SAC points out that deviations in both directions are common. Check the grade of the specific route.

Is the SAC scale the same as the blue, red and black trail classification?

No. The blue–red–black classification of mountain trails used in Bavaria and parts of Austria is a separate three-level system. And in some countries the colour of a waymark has nothing to do with difficulty at all — in the Czech Republic and Slovakia, for example, colours distinguish trails and their role in the network, not how hard they are.

Sources

The grade definitions are translated and summarised from the Swiss Alpine Club’s own document; where this page talks about OpenStreetMap, it follows the OSM Wiki. Last reviewed in October 2026.

This page explains a grading system. It cannot assess a specific route, the conditions on the day or your own ability — that judgement remains yours.

SAC hiking scale: what T1 to T6 mean