Mei Hua Yi Shu: Casting a Hexagram from Time and Numbers

Mei Hua Yi Shu (梅花易数, "Plum Blossom Numerology") is an I Ching method traditionally attributed to the Song-dynasty philosopher 邵雍 (Shao Yong). The story goes that he cast a hexagram after seeing two sparrows fight on a plum branch — hence the name. Instead of tossing coins, Mei Hua derives a hexagram from numbers: the date and hour, a count of things observed, or numbers the asker chooses. It then reads the relation between two trigrams through the five elements.

The eight trigrams and their numbers

Mei Hua uses the "Earlier Heaven" (先天) numbering of the eight trigrams:

Any number can be reduced to a trigram by taking its remainder after division by eight (a remainder of zero counts as 8, 坤).

Time casting

The classic time method uses the lunar calendar:

1. Upper trigram = (year branch number + lunar month + lunar day) mod 8. The year branch counts 子 = 1 through 亥 = 12.
2. Lower trigram = (year branch number + lunar month + lunar day + hour branch number) mod 8, with the hour counted 子 = 1 through 亥 = 12.
3. Moving line = the same total mod 6 (zero counts as 6), counted from the bottom.

Because the inputs are the moment of casting, everyone casting in the same two-hour period gets the same hexagram — Mei Hua treats the moment itself as meaningful.

Number casting

With two numbers — chosen, counted or observed — the first gives the upper trigram (mod 8), the second the lower trigram (mod 8), and their sum (often plus the hour number) gives the moving line (mod 6). The calculator shows every remainder step so you can follow the arithmetic.

Body and use

Mei Hua's core idea is the relation between two trigrams:

• The trigram without the moving line is the body (体) — the asker.
• The trigram with the moving line is the use (用) — the matter asked about.

Their five-element relation gives the basic reading:

The season matters too: a body trigram whose element is in season is stronger and can soften an unfavourable relation.

Mutual and changed hexagrams

Two more hexagrams extend the reading:

• The mutual hexagram (互卦) takes lines 2–4 as its lower trigram and lines 3–5 as its upper. It is read as the middle of the process.
• The changed hexagram (变卦) is the primary hexagram after the moving line flips. It is read as the outcome.

Read the trigrams of both against the body in the same way as the use trigram.

External signs

Classical Mei Hua also uses external signs (外应) — sounds, colours, directions, objects noticed at the moment of casting — as additional trigrams. These are personal and cannot be computed; the calculator focuses on the numerical structure.

Mei Hua and Liu Yao

Liu Yao attaches stems and branches to each line and reads lines individually; Mei Hua reads trigram relations. Mei Hua is quicker and more intuitive, Liu Yao more systematic. See Liu Yao vs Mei Hua and the three-coin method.

Origins

Mei Hua Yi Shu (梅花易数, "Plum Blossom numerology") is traditionally attributed to the Song dynasty scholar Shao Yong (邵雍). The well-known story tells of him casting a hexagram after seeing two sparrows fight on a plum branch, and correctly anticipating a small event the next day. Whatever the historical details, the method's defining feature is clear: hexagrams can be cast from numbers drawn from time, objects, sounds or observations, without coins or yarrow stalks.

A worked time casting

Time casting uses the lunar date and the hour branch. The usual formula:

1. Upper trigram: (year branch number + lunar month + lunar day) mod 8, where 子=1 … 亥=12 and a remainder of 0 counts as 8.
2. Lower trigram: (that sum + hour branch number) mod 8.
3. Changing line: (the same total including the hour) mod 6, with 0 counting as 6.

Trigram numbers follow the Earlier Heaven order: 乾1, 兑2, 离3, 震4, 巽5, 坎6, 艮7, 坤8. Suppose a 午 year (7), lunar month 3, day 15, 辰 hour (5). The first sum is 25, and 25 mod 8 = 1, so the upper trigram is 乾. Adding the hour gives 30, and 30 mod 8 = 6, so the lower trigram is 坎. The changing line is 30 mod 6 = 0, which counts as 6 — the top line. The primary hexagram is 天水讼 (乾 over 坎). The Mei Hua tool performs these steps and shows the arithmetic.

Reading body and use in more detail

The trigram without the changing line is the body (体), representing the querent; the one with the changing line is the use (用), representing the matter. Their elements are compared:

The mutual hexagram shows the process and the changed hexagram the outcome; each is read by the same body/use logic. Season also matters: a body trigram whose element is prosperous in the current season is better able to withstand a controlling use.

Mei Hua, Liu Yao and BaZi

Mei Hua is fast and image-based. Liu Yao attaches stems and branches to every line and is more systematic. BaZi describes a person rather than a question. Many practitioners use BaZi for background, and one of the divination methods for specific questions. The comparison pages set the methods side by side.

Using it responsibly

Ask one clear question, cast once, and record the result. Re-casting until you like the answer defeats the purpose. Treat the reading as a prompt for reflection, not a decision.

Reading the worked example

Continuing the example above — 天水讼 with the top line changing:

• Body and use: the changing line is in the upper trigram 乾, so 乾 is the use and the lower trigram 坎 is the body. 乾 is metal, 坎 is water; metal produces water, so the use produces the body — traditionally a favourable relation.
• Mutual hexagram: lines 2–4 and 3–5 of 讼 give 离 (lower) and 巽 (upper), the hexagram 风火家人. Wood (巽) produces fire (离); for a water body, fire is something the body controls and wood is something it produces — the process involves effort and expenditure.
• Changed hexagram: changing the top line of 乾 gives 兑, so the result is 泽水困. 兑 is metal, which still produces the 坎 water body — the outcome remains supportive, though the hexagram name 困 suggests constraint along the way.

A reader would summarise: help is available, the process demands effort, the outcome is supportive but may feel constrained. The Mei Hua tool shows the same three hexagrams and body/use elements for any cast.

Seasonal strength in Mei Hua

The body trigram's element is also weighed against the season. In autumn, metal is prosperous, so a metal body is strong; in summer, metal is weak. A favourable relation with a weak body is read more cautiously than the same relation with a strong body. This mirrors the role of season in BaZi and is one reason the casting time matters.

Key points

• Mei Hua casts hexagrams from numbers taken from time, objects or observations.
• Time casting uses the year branch number, the lunar month and day, and the hour branch number, with mod 8 for trigrams and mod 6 for the changing line.
• Trigram numbers follow the Earlier Heaven order: 乾1, 兑2, 离3, 震4, 巽5, 坎6, 艮7, 坤8.
• The trigram without the changing line is the body (the querent). The one with it is the use (the matter).
• Use producing body is most favourable. Use controlling body is least favourable.
• The mutual hexagram shows the process, and the changed hexagram shows the outcome.
• The body element's seasonal strength modifies every judgement.
• Ask one clear question, cast once, and record the result.

Key terms in this article

Trigram · 八卦

The eight trigrams — 乾兑离震巽坎艮坤 — are three-line figures associated with heaven, lake, fire, thunder, wind, water, mountain and earth, and with five-element attributes. Mei Hua Yi Shu reads the relation between the body and use trigrams.

Body and Use · 体用

In Mei Hua Yi Shu the trigram without the moving line is the body (体, the asker) and the trigram with it is the use (用, the matter). The five-element relation between them — generating, controlling or same — is the core of the reading.

Hexagram · 卦

A hexagram is a figure of six lines, each solid (yang) or broken (yin), built from two trigrams. There are 64 hexagrams in the I Ching. Liu Yao and Mei Hua Yi Shu both produce a primary hexagram and, through moving lines, a changed one.

Changing Line · 动爻

A changing (moving) line is an old yang or old yin that flips to its opposite, producing the changed hexagram. In the three-coin method, three heads or three tails give a moving line.

Common questions

Do I need the lunar date? For time casting, yes; the tool converts automatically.

What if a remainder is zero? It counts as 8 for trigrams and 6 for the moving line.

Can I cast for someone else? Traditionally the asker casts; the body trigram represents whoever asks.

Try it in the Mei Hua tool, or read the Mei Hua FAQ.