What is SPKGI?
SPKGI (Indonesian Mountain Difficulty Rating System) is a standardized assessment framework developed to determine the difficulty level of hiking and climbing routes on mountains throughout Indonesia. This system was created and developed by Hendri Agustin to streamline the operations of Indonesia Mountain & Nature Consultant.
The system evaluates each route using eleven (11) primary indicators, with every indicator scored on a scale from 1 (Very Easy) to 5 (Very Difficult). The maximum possible score is 55 points.
Each indicator represents a specific aspect of mountain conditions, such as terrain, elevation, navigation, weather, and environmental hazards. The combined score determines the overall difficulty grade of a particular route.
Since different routes on the same mountain often present different challenges, a single mountain may receive multiple SPKGI grades, depending on the route being assessed.
Purpose of SPKGI
SPKGI was developed to establish a standardized and objective mountain difficulty rating system for Indonesia—from Aceh to Papua.
The framework evaluates mountain routes using eleven key indicators that reflect:
- Mountain elevation
- Hiking distance and expedition duration
- Elevation gain
- Terrain and geological characteristics
- Vegetation and forest density
- Weather and microclimate
- Volcanic hazards
- Accessibility and logistics
- Navigation complexity
- Objective hazards (cliffs, steep drops, exposed terrain, etc.)
- Alpine environmental conditions (snow, ice, and hypothermia risk)
The objective of SPKGI is to provide a consistent and reliable reference for:
- Independent hikers
- Mountain guides
- Expedition planners
- Outdoor consultants
- Tour operators
- National Parks
- Search and Rescue (SAR) organizations
- Researchers and outdoor professionals
SPKGI Assessment Structure
The SPKGI framework consists of:
- 11 Assessment Indicators
- Scoring Scale: 1 (Very Easy) to 5 (Very Difficult) for each indicator
- Maximum Total Score: 55 points
- Final Classification: SPKGI Grades G1–G6
By applying a standardized methodology, SPKGI makes it possible to build a national mountain difficulty database and provide objective, comparable information for hiking routes across Indonesia.
The Eleven Official SPKGI Indicators
Each hiking route is assessed using the following eleven indicators. Every indicator receives one score between 1 and 5, representing the overall condition of that specific factor. The combined score determines the final SPKGI grade.
1. Mountain Elevation
Evaluates the elevation of the mountain’s highest summit above sea level.
| Score | Elevation |
|---|---|
| 1 | Below 1,000 m |
| 2 | 1,000–1,999 m |
| 3 | 2,000–2,999 m |
| 4 | 3,000–3,999 m |
| 5 | 4,000 m and above |
2. Hiking Distance & Expedition Duration
Measures the total round-trip distance and typical expedition duration.
| Score | Criteria |
| 1 | Less than 10 km / 1 day |
| 2 | 10–19 km / 1–2 days |
| 3 | 20–29 km / 2–3 days |
| 4 | 30–50 km / 3–4 days |
| 5 | More than 50 km / 5 days or longer |
3. Elevation Gain
Measures the total net vertical ascent from the trailhead to the summit.
Elevation Gain = Summit Elevation − Trailhead Elevation
| Score | Elevation Gain |
| 1 | Less than 500 m |
| 2 | 500–999 m |
| 3 | 1,000–1,499 m |
| 4 | 1,500–1,999 m |
| 5 | 2,000 m or more |
4. Terrain & Geological Characteristics
Evaluates terrain conditions, slope angle, rock stability, and overall surface difficulty.
| Score | Criteria |
| 1 | Wide, stable, relatively flat trail |
| 2 | Firm ground with well-defined paths |
| 3 | Mixed terrain with roots and rocks |
| 4 | Loose volcanic sand, slippery slopes, steep rocky sections |
| 5 | Cliffs, exposed ridges, unstable rock, extreme terrain |
5. Vegetation & Forest Density
Assesses vegetation density and forest characteristics along the route.
| Score | Criteria |
| 1 | Open grassland or savanna |
| 2 | Open woodland |
| 3 | Moderate forest with shrubs |
| 4 | Dense tropical forest |
| 5 | Primary rainforest with extremely dense vegetation and high humidity |
6. Weather & Microclimate
Evaluates rainfall, fog, temperature, humidity, and local weather conditions.
| Score | Criteria |
| 1 | Stable weather, warm temperatures, infrequent rain |
| 2 | Moderate rainfall and light winds |
| 3 | Frequent afternoon fog and cool nights |
| 4 | Heavy rainfall, dense fog, low temperatures |
| 5 | Severe weather, storms, extreme winds, temperatures approaching 0°C |
7. Volcanic Hazard
Evaluates volcanic activity and crater-related hazards.
| Score | Criteria |
| 1 | Non-volcanic mountain |
| 2 | Extinct volcano |
| 3 | Dormant volcano |
| 4 | Active volcano with minor volcanic gas activity |
| 5 | Active volcano with eruption potential and hazardous volcanic gases |
8. Accessibility & Logistics
Measures the difficulty of reaching the trailhead and the availability of transportation, supplies, and water.
| Score | Criteria |
| 1 | Easily accessible by private vehicle with complete logistical support |
| 2 | Good road access and basic logistical facilities |
| 3 | Requires four-wheel-drive vehicle; nearest village is relatively distant |
| 4 | Accessible only by motorcycle followed by hiking to the trailhead |
| 5 | Requires helicopter or small aircraft; no local logistical support available |
9. Navigation & Route Finding
Evaluates trail clarity and the level of navigation required.
| Score | Criteria |
| 1 | Wide, obvious, and well-maintained trail |
| 2 | Clearly marked route with signs or trail markers |
| 3 | Several junctions requiring local knowledge |
| 4 | Faint or unmarked trails requiring strong navigation skills |
| 5 | No established trail; GPS, compass, and topographic maps are essential |
10. Objective Hazards
Evaluates natural hazards that may result in serious injury or fatal accidents.
| Score | Criteria |
| 1 | Minimal objective hazards |
| 2 | Minor slips, roots, and small stream crossings |
| 3 | Steep slopes and large root systems |
| 4 | Cliffs and steep rock faces adjacent to the trail |
| 5 | Narrow summit ridges, exposed cliffs, and high fall potential |
11. Alpine Environmental Conditions
Evaluates alpine hazards that distinguish high-altitude alpine environments from tropical mountain conditions.
| Score | Criteria |
| 1 | No snow or ice; temperatures generally above 10°C |
| 2 | Cool foggy conditions; nighttime temperatures below 10°C |
| 3 | Cold and humid alpine zone with occasional frost |
| 4 | Permanent ice or remnant glaciers; nighttime temperatures below 0°C |
| 5 | Active snowfields, solid ice, hail, high hypothermia risk, and mandatory acclimatization |
SPKGI Grade Classification
| Total Score | SPKGI Grade | Difficulty Level |
|---|---|---|
| 11–15 | G1 | Very Easy |
| 16–25 | G2 | Easy |
| 26–35 | G3 | Moderate |
| 36–43 | G4 | Difficult |
| 44–49 | G5 | Very Difficult |
| 50–55 | G6 | Extreme Alpine Expedition |
The SPKGI classification system consists of six (6) difficulty grades, each representing a specific range of total assessment scores.
It is possible for all routes on the same mountain to fall within the same SPKGI grade while having different total scores. This difference indicates that, although the routes share the same overall difficulty classification, one route may still be objectively more demanding than another.
For example, two routes may both be classified as SPKGI Grade G4, but a route with a total score of 41 is considered more challenging than another route with a score of 36, even though both remain within the same grade category.
This scoring system provides a more detailed and objective comparison between routes while maintaining a simple six-grade classification that is easy to understand and apply.