Bagua Mirror (八卦镜) — Meaning, Concave vs Convex & Placement

What Is the Bagua Mirror (八卦镜)?

The Bagua mirror (Bagua jing, 八卦鏡) is a round mirror engraved with the eight trigrams of the Later Heaven arrangement surrounding a central reflective disc. It is one of the oldest remedies in Chinese Feng Shui — and visually the most recognizable. Walk through any older neighborhood in Hong Kong, Taipei, or Penang and you will see them mounted above front doors and windows, angled toward a street corner, a T-junction, or the sharp roofline of an opposing building.

The name itself is precise: bagua (八卦) is the eight-trigram system used to map Qi flow across space and time; jing (镜) means mirror. The two together tell you what the object does — it mirrors back the qi it sees. Whether it mirrors it back inward (absorbing it) or outward (repelling it) depends on the curvature of the central disc, and that is the first decision you must make when choosing one.

The deeper classical purpose is to deal with what is called sha qi (煞气) — the sharp, hostile, or stagnant Qi that comes from hostile environmental formations. Sharp Qi is produced when an angular form — a street corner, the roof of a neighboring building, a road aimed straight at your door — drives a tight stream of energy toward the home. Standard examples include:

• The home sits at the end of a road or at a T-junction (冲煞, chong sha — "rushing attack sha")
• A sharp corner or roof ridge of a nearby building points directly at the front door (尖角煞, jian jiao sha — "sharp-corner sha")
• The front door faces a hospital, cemetery, temple, transformer, or large utility pole
• Two front doors face each other across a narrow lane (对门煞, dui men sha — "facing-door sha")
• A busy expressway, railway, or bridge runs close to the home (路冲, lu chong)
• A long corridor or hallway inside the home ends directly at a bedroom, kitchen, or main door (穿心煞, chuan xin sha — "piercing-heart sha")

Three things distinguish a classical Bagua mirror from a souvenir:

1. Shape and curvature: Convex (bulging out, 凸鏡), concave (caving in, 凹鏡), or plain flat with the eight trigrams only. The shape determines whether the mirror absorbs sha qi or deflects it.
2. Material: Cast bronze, brass, polished steel, or occasionally gilded wood. These are the strongest forms. Cheap plastic-and-foil tourist versions do not carry sustained Qi.
3. Engraving quality: The eight trigrams (乾 Qian, 坤 Kun, 震 Zhen, 巽 Xun, 坎 Kan, 离 Li, 艮 Gen, 兑 Dui) must be correctly arranged in the Later Heaven sequence. Mis-engraved mirrors are treated as inauspicious objects, not remedies.

Concave vs Convex Bagua Mirror (凹鏡 vs 凸鏡)

This is the single most important decision you will make, and almost everything else about the Bagua mirror is downstream of it.

Convex Bagua mirror (凸鏡, tu jing) — the center bulges outward, the way a fish-eye lens does. Its function is to reflect, disperse, and turn back the hostile Qi aimed at the home. The reflected Qi is defused over a wider arc rather than sent back as a single tight ray. This is the form you see most often on residential front doors facing a T-junction or a sharp corner.

Concave Bagua mirror (凹鏡, ao jing) — the center curves inward like a small bowl. Its function is to absorb hostile Qi and pull it into the mirror. Classical Chinese practice used the concave form sparingly and only when a specific storehouse-of-Qi explanation was needed. For most homes, the concave form is not recommended: it pulls the sha into the mirror's "bowl," and what the mirror stores can eventually overflow back into the home.

Plain flat Bagua (平面八卦) — the most common form, with the eight trigrams engraved around a flat mirror or just a flat disc. It does not deeply reflect or absorb; it is a symbolic marker. Used where the hostile formation is mild or where the primary purpose is symbolic alignment with the home's sitting and facing direction.

Which one to use

• Use convex when the home faces a T-junction, a sharp corner, an opposing front door, a road, or any formation that is sending Qi straight at the home. This is the default in roughly 80% of cases.
• Use concave only when advised by an experienced practitioner for a specific storehouse-of-Qi situation — for example, an empty lot that "leaks" Qi outward from the property, where you want to pull some of it back. Most retail Feng Shui books discourage the concave form for beginners.
• Use plain flat when the formation is mild (e.g., a corner three houses down) or when the home primarily needs symbolic/protective marking without major deflection.
• For readers who already work with Five Element and BaZi logic, the curvature choice interacts with the element of the formation. A wood-heavy external pressure (a tall green tree, a wooden lamp post, a leafy upturned branch) is met with a more metal-strong convex mirror, because Metal controls Wood in the productive-control cycle.

When to Use a Bagua Mirror — Sha Qi, Hostile Formations & Annual Stars

The Bagua mirror is not a general-purpose luck charm. It is a remedy for a specific class of problem: hostile environmental Qi. Use it when at least one of the following conditions is unambiguously present.

1. The front door faces a hostile formation

This is the most common call for a Bagua mirror. The doorway is the mouth of the home — where Qi enters most easily. When the doorway sits at the end of a road, faces a sharp corner, or opens onto a busy lane carrying fast-moving Qi, the home receives a stream of energy that is too tight, too fast, or coming from the wrong place. A convex mirror hung above the door turns that stream aside.

2. A sharp object inside the home points at a seat

A column, a sharp corner of a counter, the edge of a staircase descending toward a bed or a desk — these are interior sha formations. Sometimes the remedy here is the Bagua mirror, sometimes a partition, sometimes a salt-water cure. The mirror is reserved for the worst of them.

3. The annual Flying Star chart places a problem star on the front door

Every year, the Flying Stars rotate through the nine sectors of the home. The #2 Black-Mist sickness star, the #3 Jade-Liu dispute star, and the #7 Red-Phthisy violence/robbery star are the three most "met" with a Bagua mirror when they land in the front door sector or in the sector where a person regularly sits. The remedy is renewed each year as the stars move.

4. A specific BaZi clash with a current luck pillar

Some luck pillars arrive "armed" — the year or decade carries a sharp opposing branch, a heavy metal clash, or an open road of Qi. For a Day Master whose chart is hit particularly hard, a Bagua mirror outside the front door is part of the year's external remedies, alongside protective wearables and salt-water cures.

When NOT to use a Bagua mirror

• The home is in a stable, open cul-de-sac or a quiet residential street with no hostile formation. A Bagua mirror there is decoration pretending to be a remedy.
• The chart is already heavy with Metal and cannot tolerate more — adding a metal Bagua mirror pushes the imbalance further. Run a Five Element check first.
• The "problem" is a personal one (career, relationship, health) with no environmental input. A mirror on the wall will not fix an internal misalignment.
• You want a mirror only because the neighbor hung one. Mirroring a neighbor's remedy is one of the most common causes of compounded sha in a street.

Placement: Front Door, Window, Direction, Height

Correct placement solves roughly 70% of a Bagua mirror's effectiveness. Most failed placements fail in one of three ways: too low, indoors, or pointed at the wrong target.

The basic rules, in order of priority

1. Hang it outside the home, not inside. Outside the front door above the frame, or outside the window that faces the hostile formation. An indoor mirror, by classical logic, sends the deflected Qi back into the home — which is exactly the opposite of the intended function.
2. Hang it high. Above head height, ideally with the center of the mirror at or above the lintel of the door. A Bagua mirror at eye level competes with the eye; a Bagua mirror above the door presides over the entrance.
3. Aim it at the offending formation — not at the open sky, not at the neighbor, not at the street. The mirror's center should be pointed at the source of sha qi. If a sharp corner three houses down points at the home, the mirror angles toward that corner. If a T-junction delivers Qi from the south, the mirror faces south.
4. For the front door, place it slightly off-center to the side of the road Qi. If the road Qi comes from the left (sha pan sha, 煞偏), place the mirror above the left side of the door frame. If it comes from the right, place it above the right side. Centering it can be acceptable for a perfectly straight-on lane.
5. For interior "heart-piercing" corridors, use a flat Bagua disc inside, not a convex mirror. A long hallway that ends at a main door or bed is a chuan xin sha. A flat Bagua disc mounted on the end wall symbolically seals the corridor; a convex one indoors is not appropriate.

Height, size, and number

Standard residential Bagua mirrors are between 4 and 12 inches (10–30 cm) in diameter. Single mirror is the rule. Stacking two or three Bagua mirrors to "be stronger" is a folk mistake — it signals visible aggression to passers-by and turns the home into a marked target. One well-placed mirror, appropriately sized for the doorway, is sufficient.

For tall facades or apartment corridors where the formation is far away, a slightly larger mirror (20–30 cm) catches more reflected Qi. For close-range sharp corners (a roofline two meters from the door), a smaller mirror (10–15 cm) at close height is enough and reads as less aggressive.

The Annual Flying Star Tie-In (#2, #3, #5, #7)

The single most predictable reason practitioners prescribe a Bagua mirror is the annual Flying Star chart. Every Chinese new year the nine stars rotate through the sectors of the home, and four of them — #2, #3, #5, and #7 — are considered inauspicious enough that remedies are deployed when they enter the front door sector or the sector where the head of household regularly sits or sleeps.

How to know which star is where

You need two pieces of data: the home's facing direction (the wall where the front door sits), and the period of construction (the era when the home was built — most standing homes sit in Period 8, 2004–2023, and the transition into Period 9 began in 2024). For each year a published Flying Stars chart shows where each annual star lands. Practitioners also draw the 20-year mountain and water stars (chen yen yen, 辰巽巽) for the property, which can overlay or conflict with the annual stars.

The list below is the typical mirror prescription, star by star.

Each remedy should be deployed at the start of the new lunar year (typically the day after Chinese New Year) and removed at the year-end cleaning. A mirror left untouched for years accumulates the energy of all the stars that passed through the sector — sometimes helpful, sometimes harmful, never neutral. For a fuller yearly update, see our Five Elements explained guide and the running annual forecasts published on the home page.

Mistakes to Avoid — Especially Pointing Into the Neighbor

The reason the Bagua mirror has a bad reputation among casual writers is that almost all the failures are user error. The mirror itself is straightforward; the placement is where it goes wrong.

The neighbor mistake, in detail

It deserves its own paragraph because it is the single most reported failure case. When two front doors face each other across a narrow lane, the temptation is to put a Bagua mirror on your own door aimed at the neighbor's door — the logic being "they shoot Qi at me, I shoot it back." This is the classical setup for what Chinese practitioners call a double-blow mirror (双冲镜). The two households then ping sha back and forth, escalating every year: arguments, illness, lost money, broken relationships. The deeper problem is that the mirror aimed at a person is the worst possible configuration — it sends hostile Qi directly into a living being rather than dispersing it.

If you must deflect Qi coming from a neighbor's door, the mirror should be angled to the wall beside the door, to the ground in front, or to the sky above. The hostile Qi is neutralized; the neighbor's home receives no ray. Many practitioners prescribe, instead, a small pair of Fu Dogs (石狮) at the base of the door — they "hold the line" without firing back — or a row of bamboo planted between the doors to soften the lane Qi.

Placement inside the home

Most practitioners do not recommend placing a Bagua mirror inside the home at all. The one acceptable indoor use is the flat Bagua disc at the end of a long corridor (chuan xin sha) or above a bedroom door that opens directly onto a staircase — but even then a partition curtain, a salt-water cure, or a small mountain of five-elementally-correct objects is usually preferred. For a tailored reading on whether your home actually needs one (and where), the matching free mini reading shows your element balance and current yearly pressures in under a minute.

Bagua Mirror, Five Elements & BaZi — How It Connects

The Bagua mirror is not a stand-alone charm. It is a Metal-dominant remedy, and like every classical remedy it has to be checked against the chart of the people who live under it.

The element logic

The round form carries Metal Qi — the same Metal Qi as a metal-element bracelet or a crystal sphere. Metal controls Wood (金克木), and the most common sha Qi coming at a front door is Wood-Qi-heavy pressure: a leafy tree, an upturned lamp post, a sharp branch of road aimed at the door. The metal disc cuts that excessive incoming Wood. Metal also produces Water, so when the chart needs Water (wisdom, flow, communication), a metal Bagua mirror doubles as a water-supporting remedy.

BaZi Day Master pairing

If you don't yet know which element is dominant in your chart, the free instant reading builds the Day Master and elemental profile in under a minute. From there you can decide whether a Bagua mirror genuinely serves your home — or whether the right remedy this year is something with more Water, less Fire, or no metal at all. Matched remedies — for the front door as well as for the personal layer — are laid out on the products page, and a page like our Feng Shui pagoda guide covers the parallel remedy for the study.

Frequently Asked Questions