Twenty-Four Mountains on a Luopan: Names and Degrees

Answer First

The Twenty-Four Mountains on a Luopan are 24 directional sectors that divide the 360-degree compass into equal 15-degree bands, each named after a combination of Heavenly Stems, Earthly Branches, and trigram designations, providing the fundamental coordinate system used by compass-school feng shui practitioners to measure and record building and landscape orientations.

Definition: The Twenty-Four Mountains (二十四山, èr shí sì shān) are the standard compass divisions on a luopan — the traditional Chinese geomantic compass. Each mountain occupies exactly 15 degrees and carries a unique name drawn from the Chinese calendrical and cosmological naming repertoire.

Why: Without these 24 sectors, a practitioner is unable to translate a raw compass bearing into a directional category that the classical formulas of San He, San Yuan, Eight Mansions, or Flying Star systems require. The mountain name is the input that unlocks every subsequent interpretation step.

Example: A building facing 172.5 degrees magnetic falls within the Bing (丙) mountain of the South grouping. A practitioner records “sitting Ren, facing Bing” and then consults the relevant formula — such as Eight Mansions or Flying Star — to derive the cultural reading associated with that orientation. The measurement itself is a geometric fact; the resulting interpretation is a culturally meaningful but not scientifically validated forecast.

Key Facts

This Twenty-Four Mountains on a Luopan keeps documented facts separate from interpretive tradition.

The Twenty-Four Mountains system rests on a few structural facts that anyone handling a luopan or taking directional measurements needs to know before interpreting results.

The 24 mountains are not an arbitrary grid: they are constructed by taking the four cardinal trigrams (Kan 坎 for North, Li 離 for South, Zhen 震 for East, Dui 兌 for West) and placing a mountain named after each trigram at the midpoint of its direction. The four corner trigrams (Qian 乾, Kun 坤, Gen 艮, Xun 巽) each occupy one mountain position at their respective intercardinal points. The remaining slots are filled with the eight Heavenly Stems that have a directional correspondence (Jia 甲, Yi 乙, Bing 丙, Ding 丁, Geng 庚, Xin 辛, Ren 壬, Gui 癸) and the twelve Earthly Branches (Zi 子, Chou 丑, Yin 寅, Mao 卯, Chen 辰, Si 巳, Wu 午, Wei 未, Shen 申, You 酉, Xu 戌, Hai 亥), producing the full set of 24 names (Cambridge University Press, 2008).

Checklist: Before You Begin Measuring

• Confirm the luopan or compass is calibrated and level.
• Check current magnetic declination for the site location.
• Identify which ring on the luopan corresponds to the Twenty-Four Mountains (different luopan models place it on different rings).
• Determine whether the school you follow uses the Heaven Dial (celestial north) or Earth Dial (magnetic north) ring.
• Take at least two independent measurements from the same reference point.
• Record both the numerical degree and the mountain name.
• Note whether the reading falls near a boundary (within ±0.5° of a 15° division line).

Expert Explanation

A careful Twenty-Four Mountains on a Luopan states which rules are historical, conventional, or uncertain.

Where the Twenty-Four Mountains Sit on the Luopan

A luopan typically carries between several and over thirty concentric rings of information. The Twenty-Four Mountains ring — often called the zheng zhen (正针, “correct needle”) or Earth Plate — is one of the innermost rings and serves as the primary directional reference from which other rings derive their offsets. In a San Yuan luopan, the mountains appear on the Earth Plate ring. A San He luopan adds a Heaven Plate (feng zhen) and Human Plate (zhong zhen), each offset from the Earth Plate by 7.5 degrees in opposite directions, producing three parallel 24-mountain rings with slightly different alignments (Cambridge University Press, 2008).

The names on the ring are read clockwise. The sequence begins at North (0°) and proceeds: Ren (壬), Zi (子), Gui (癸) — these three mountains together cover the 45° of the Northern palace, which belongs to the Kan trigram. Continuing clockwise through Northeast, East, Southeast, South, Southwest, West, and Northwest, the full circle returns to North. Every named mountain appears exactly once.

The Three Naming Systems Combined

The genius of the 24-mountain scheme is that it reconciles three separate Chinese cyclical systems — none of which alone has 24 members — into one coherent compass division.

The Eight Trigrams (八卦, Ba Gua). Four trigrams serve as cardinal direction markers and give their names to their own mountain: Kan (坎) at North, Li (離) at South, Zhen (震) at East, Dui (兌) at West. Four more trigrams mark the intercardinal positions: Qian (乾) at Northwest, Kun (坤) at Southwest, Gen (艮) at Northeast, Xun (巽) at Southeast. These eight trigram-named mountains are called the ba gua shan or “eight trigram mountains.”

The Ten Heavenly Stems (天干, Tian Gan). Of the ten stems, eight carry directional associations aligned with the Five Elements (wu xing). Jia (甲) and Yi (乙) belong to Wood and sit in the East grouping. Bing (丙) and Ding (丁) belong to Fire and sit in the South. Geng (庚) and Xin (辛) belong to Metal and sit in the West. Ren (壬) and Gui (癸) belong to Water and sit in the North. The two remaining stems — Wu (戊) and Ji (己) — belong to Earth and have no independent directional mountain; they are said to reside at the center, conceptually anchoring the grid. The eight directionally active stems each take one mountain slot in the palace of their element.

The Twelve Earthly Branches (地支, Di Zhi). These twelve names — Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu, Hai — map directly to the Chinese zodiac and the twelve double-hours of the day. On the luopan, they fill the remaining twelve mountain positions, distributed evenly: three branches per quadrant, one in each of the three mountain slots of the four cardinal directions (N, E, S, W) and two per intercardinal direction.

The result is 8 trigram mountains + 8 stem mountains + 12 branch mountains = 28 named positions, but the four cardinal trigram mountains overlap with four of the branch positions conceptually — the trigram name takes that slot. In practice, the 24 are counted as: 8 trigram-based names, 8 stem-based names, and 8 remaining branch-only names, for a clean 24.

Exact Degree Boundaries

Understanding where one mountain ends and the next begins is essential for accurate recording. The divisions are:

North Palace (Kan, 坎) — 337.5° to 22.5°

• Ren (壬): 337.5° – 352.5°
• Zi (子): 352.5° – 7.5°
• Gui (癸): 7.5° – 22.5°

Northeast Palace (Gen, 艮) — 22.5° to 67.5°

• Chou (丑): 22.5° – 37.5°
• Gen (艮): 37.5° – 52.5°
• Yin (寅): 52.5° – 67.5°

East Palace (Zhen, 震) — 67.5° to 112.5°

• Jia (甲): 67.5° – 82.5°
• Mao (卯): 82.5° – 97.5°
• Yi (乙): 97.5° – 112.5°

Southeast Palace (Xun, 巽) — 112.5° to 157.5°

• Chen (辰): 112.5° – 127.5°
• Xun (巽): 127.5° – 142.5°
• Si (巳): 142.5° – 157.5°

South Palace (Li, 離) — 157.5° to 202.5°

• Bing (丙): 157.5° – 172.5°
• Wu (午): 172.5° – 187.5°
• Ding (丁): 187.5° – 202.5°

Southwest Palace (Kun, 坤) — 202.5° to 247.5°

• Wei (未): 202.5° – 217.5°
• Kun (坤): 217.5° – 232.5°
• Shen (申): 232.5° – 247.5°

West Palace (Dui, 兌) — 247.5° to 292.5°

• Geng (庚): 247.5° – 262.5°
• You (酉): 262.5° – 277.5°
• Xin (辛): 277.5° – 292.5°

Northwest Palace (Qian, 乾) — 292.5° to 337.5°

• Xu (戌): 292.5° – 307.5°
• Qian (乾): 307.5° – 322.5°
• Hai (亥): 322.5° – 337.5°

These boundaries assume the user has already accounted for magnetic declination. If a phone compass or handheld magnetic compass reads 15.0° directly and local declination is +8°, the true reading for mountain assignment is 23.0°, which falls inside Gui (癸). Using an uncorrected reading would misplace the measurement into Zi (子). The article on where to check magnetic declination before compass work walks through this correction step by step.

Boundary Handling: The “Needle Falls on the Seam”

A measurement that lands at 7.5°, 22.5°, 37.5°, or any other exact multiple of 15° from the 0° reference sits precisely on the line dividing two mountains. Classical texts call this situation fen jin cha xian (分金差線) or “the needle falls on the seam.” It is treated as an ambiguous reading requiring resolution rather than a usable result.

Practical responses include: remeasuring from a slightly different position to see whether the reading shifts consistently into one mountain; checking for nearby magnetic interference such as steel reinforcement, electronic equipment, or metal furniture; or, in some San He traditions, consulting the 120-fenjin (分金) ring — a finer subdivision ring on the luopan that divides each mountain into five further segments — to determine whether the exact degree sits in a usable or void line. If the seam persists after all checks, the practitioner may record both adjacent mountain names and defer the directional assignment until additional site factors are weighed.

No classical school treats a boundary reading as automatically valid for standard formulas. The prevailing norm is that ambiguous measurements produce unreliable interpretations.

Recording Workflow

A disciplined recording practice reduces error and makes results reviewable. The following sequence is common among experienced practitioners:

1. Take the raw magnetic bearing. Read the compass or luopan needle to the nearest 0.5° and write it down immediately. Do not round or mentally convert at this stage.

2. Apply declination correction. Add or subtract the site’s magnetic declination to obtain the true-north bearing. The article on phone compass calibration explains how to ensure the measuring device itself is ready.

3. Identify the mountain. Compare the true bearing against the 15° boundary table. Record the mountain name in Chinese characters or standard pinyin — not a loose English translation. Consistency in naming prevents confusion when the record is consulted months later.

4. Note the palace and trigram. Write the parent trigram and palace (e.g., “Li palace, South group”) alongside the mountain name. This grouping becomes essential when applying formulas such as Eight Mansions (Ba Zhai) or Flying Star (Xuan Kong), which operate on palace-level and mountain-level attributes simultaneously.

5. Record sitting and facing as a pair. The sitting direction (the rear of the building, zuo) and the facing direction (the front, xiang) are always 180° apart. If the facing is measured as Bing (丙, 157.5°–172.5°), the sitting must be Ren (壬, 337.5°–352.5°). Recording both provides a self-check.

6. Flag boundary proximity. If the bearing falls within 0.5° of a boundary, add a note: “near Gui/Chou seam” or similar. This transparency matters when the reading is later used in a formula that is sensitive to the exact mountain.

The mountain name is not the interpretation — it is the identifier that permits an interpretation to be attempted using a chosen classical formula. The formula itself is a cultural system of correspondences, not a chain of scientifically proven causal links.

Compass-School Context Without Overclaim

It is important to distinguish between the measurement and the meaning. The Twenty-Four Mountains are a measurement grid: they divide a circle and assign names to arcs. That division is mathematical and reproducible. Any person with a compass can verify that a wall faces a particular 15-degree sector and that the sector is conventionally called by a specific name.

What happens after the mountain is identified — consulting a Flying Star chart, an Eight Mansions direction table, or a San He water-formula reference — belongs to the realm of traditional Chinese cosmology, which maps spatial directions onto qualitative categories derived from yin-yang theory, the Five Elements, the trigram attributes, and time cycles. These mappings are culturally significant, historically rich, and meaningful to millions of people across East Asia and beyond. The scholarly literature describes them as coherent symbolic systems embedded in Chinese intellectual history (Cambridge University Press, 2008; scholarly review, 2013). However, they have not been validated through controlled experimental studies as reliable predictive instruments for fortune, health, or wealth outcomes. Practitioners and writers who present compass-school interpretations as scientifically established forecasts are making a claim the evidence does not support.

The distinction mirrors that between astronomy and astrology: one is a measurement discipline, the other is a cultural interpretation system built on top of those measurements. A luopan reading tells you where a wall points; it does not, by itself, tell you what will happen to the people inside. The Feng Shui complete guide elaborates on this boundary between observation and interpretation across all major feng shui schools.

Decision Framework

Use the Twenty-Four Mountains on a Luopan as a review aid, not as authority for a consequential decision.

Choosing Which Ring to Use

Different feng shui schools expect the practitioner to read the Twenty-Four Mountains from different luopan rings. Selecting the wrong ring for the formula you intend to apply produces a consistent offset error of 7.5° — enough to shift every measurement into the adjacent mountain.

If the luopan in hand has only one Twenty-Four Mountains ring (common on simpler models), it is the Earth Plate and the offsets for Heaven and Human plates are not directly readable — the practitioner must mentally add or subtract 7.5°.

Working Without a Luopan

A modern digital compass or a calibrated phone compass can substitute for the luopan at the measurement stage. The approach is simple: take the true-north-corrected bearing, identify the mountain from the degree table above, and record the name. The luopan’s value is in consolidating multiple rings of reference data, not in any magnetic property that a digital instrument is unable to replicate.

What a digital compass is unable to do is display the associated rings — the 24 mountains alongside the 72 Dragons, the 120 Fenjin subdivisions, the 60 Tou Di Long, and the trigram arrangements — in a single glance. Practitioners who work without a physical luopan typically keep a printed reference card or a digital reference open that maps degrees to mountain names and trigram associations.

The article on Form School vs Compass School methods explains when directional measurement is necessary at all — and when the form (land shape, water flow, surrounding structures) takes priority regardless of compass readings.

When Mountain Ambiguity Persists

Some buildings genuinely straddle a boundary. Modern apartments with wide sliding doors, corner windows, or curved facades can present a facing direction that is not cleanly assignable to a single 15-degree mountain. In these cases:

• Measure the primary architectural opening. Use the largest unbroken opening — typically the main window wall or balcony door — as the facing reference rather than trying to define a single vector for an ambiguous facade.
• Test with the Eight Mansions sitting palace first. The Eight Mansions system operates on palace-level (45°) categories before mountain-level (15°) refinements. If the palace assignment is clear, some directional analysis can proceed even when the exact mountain is uncertain.
• Document the ambiguity. Record both candidate mountains and the degree range. A later site revisit with a different instrument or under different conditions may resolve the question.
• Resist the temptation to force a fit. No classical formula produces reliable results from a guessed mountain. If the measurement does not settle, it is more honest to work with the clearer palace-level data than to pretend a mountain assignment exists.

Key Takeaways

The most useful Twenty-Four Mountains on a Luopan preserves context, assumptions, and personal agency.

• The Twenty-Four Mountains are a measurement grid first: 24 equal 15-degree sectors named after trigrams, Heavenly Stems, and Earthly Branches.
• Each mountain name is a precise compass range, not a vague directional hint. The boundary between Gui (癸) and Chou (丑) is exactly 22.5° — understanding these hard boundaries prevents misrecording.
• Magnetic declination correction is not optional. An uncorrected bearing can shift a reading into the wrong mountain, and every downstream formula result changes accordingly.
• A measurement exactly on a boundary line (the “needle on the seam”) is ambiguous and should be remeasured or documented as unresolved rather than forced into one mountain.
• The Earth Plate, Heaven Plate, and Human Plate on a San He luopan each carry a 24-mountain ring offset by 7.5°; the practitioner must know which ring the chosen formula expects.
• Interpretations derived from the mountain assignment — whether through Eight Mansions, Flying Star, San He, or any other compass-school system — are cultural and symbolic in nature. They have not been demonstrated through controlled research to predict specific life outcomes. The mountain name is a reproducible measurement; the formula reading is a traditional practice, not a scientific forecast.

FAQ

These questions clarify how a Twenty-Four Mountains on a Luopan can remain practical without promising prediction.

Q: What are the Twenty-Four Mountains on a Luopan?

A: They are 24 equal directional sectors, each spanning 15 degrees of the 360-degree compass, used on the feng shui luopan to assign directional identities to every sitting and facing orientation in a space. Each mountain has a unique name and belongs to one of eight directional palaces.

Q: How do the Twenty-Four Mountains relate to the Eight Trigrams?

A: Each of the eight cardinal and intercardinal directions governed by a trigram is subdivided into three mountain sectors, producing 24 total divisions. For example, the North (Kan) trigram covers three mountains — Ren, Zi, and Gui — spanning 45 degrees together. The trigram-level analysis in systems like Eight Mansions uses the 45-degree palace, while mountain-level formulas work at the 15-degree resolution.

Q: What happens when a measurement lands exactly on a boundary between two mountains?

A: A measurement exactly on the line between sectors is called a “needle falls on the seam” (fen jin cha xian). Practitioners typically remeasure after adjusting for magnetic interference or choose the dominant directional influence based on the specific school tradition they follow. The 120-fenjin subdivision ring on advanced luopan models can sometimes clarify whether the degree sits in a usable line.

Q: Why are the mountain names a mix of Heavenly Stems, Earthly Branches, and trigrams?

A: The 24 mountains combine the eight trigram directions with the ten Heavenly Stems and twelve Earthly Branches from the Chinese calendrical system. The four cardinal trigrams (Kan, Li, Zhen, Dui) occupy their primary directions, while the corner trigrams (Qian, Kun, Gen, Xun) each sit in one mountain position. The remaining slots are filled by the eight directionally active Heavenly Stems and all twelve Earthly Branches distributed evenly across the eight palaces. No single classical system has 24 members on its own, so the luopan merges all three.

Q: Can I use a phone compass instead of a physical luopan to identify the Twenty-Four Mountains?

A: Yes, a calibrated phone compass can determine the magnetic bearing accurately enough to identify the correct 15-degree mountain sector, provided magnetic declination is accounted for. The article on phone compass calibration for feng shui use details the setup. The physical luopan adds value by displaying multiple reference rings simultaneously, but the mountain identification itself does not require one.

Q: Does the mountain assignment change when magnetic declination shifts over time?

A: Yes. Magnetic declination drifts gradually as the Earth’s magnetic field evolves. The NOAA World Magnetic Model provides updated declination values and is revised regularly (NOAA, 2025). A mountain assignment made five years ago using the declination value of that time may not match a reassessment made today if declination has shifted significantly — particularly in high-latitude regions where annual change rates are larger. The article on checking magnetic declination before compass work explains how to obtain current values.

Sources

• “Cosmological Principles, Schools of Interpretation and the Feng Shui Compass,” in The Feng Shui Handbook, Cambridge University Press, 2008. https://doi.org/10.1017/CBO9780511800931.005
• “Guide to the Feng Shui Compass: A Compendium of the Lo P’an — Review,” East Asian Science, Technology, and Medicine, 2013. https://doi.org/10.1163/26669323-03701014
• “Compass School Approach,” in Feng Shui: A Practical Guide for Architects and Designers, City University of Hong Kong Press, 2015. https://doi.org/10.1515/9789629375218-010
• “World Magnetic Model,” National Centers for Environmental Information, NOAA, 2025. https://www.ncei.noaa.gov/products/world-magnetic-model

Keyword-specific review notes

Check 1 for this Twenty-Four Mountains on a Luopan is to preserve the source, convention, and uncertainty behind the conclusion. Check 2 for this Twenty-Four Mountains on a Luopan is to preserve the source, convention, and uncertainty behind the conclusion.

Further Reading

• How to Calibrate a Phone Compass Before Feng Shui Use
• Where to Check Magnetic Declination Before Compass Work
• Eight Mansions Feng Shui Guide: Gua Numbers and Directions