A mora, called haku or on in Japanese, is the rhythmic unit that poetry counts. It is not the same as a syllable: しゃ is one mora and one syllable, but とう is two morae because the long vowel adds a beat. Haiku are counted in morae, not syllables.

How are small kana counted?

Small ゃ, ゅ, ょ (and their katakana forms) combine with the preceding full kana to form one mora, so きょ is a single mora. This is the yōon rule that keeps きょう at two morae rather than three.

Do ん, っ, and ー count?

Yes. The moraic nasal ん, the geminate っ (sokuon), and the long-vowel mark ー each count as one full mora on their own. This is why しんぶん is four morae and コーヒー is four morae.

Why does my haiku count differ from the English syllables?

English syllable counts often understate Japanese morae because long vowels and final ん add beats that English ignores. Counting morae is the authentic way to measure a Japanese 5-7-5, which is why translated haiku rarely keep the exact pattern.

No. Mora counting runs locally in your browser. Nothing you enter is sent to a server.

What is the Japanese Mora Counter?

Count Japanese morae (haku) the way haiku and tanka are measured: each full kana is one mora, small ゃゅょ combine with the preceding kana, and ん, っ, and long-vowel ー each add a mora. Verify 5-7-5 structure entirely in your browser. It runs free in your browser on Gera Tools, with nothing uploaded.

Japanese Mora Counter

Name: Japanese Mora Counter
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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Count Japanese morae for haiku

Japanese poetry is measured in morae (haku), not English syllables. This counter applies the classical rules so you can verify a haiku’s 5-7-5 structure or a tanka’s 5-7-5-7-7, counting each line separately.

How it works

Each kana is one mora, with three adjustments:

き + ょ  →  きょ   (small kana merges → 1 mora)
ん        →  1 mora (moraic nasal)
っ        →  1 mora (sokuon / geminate)
ー        →  1 mora (long-vowel mark)

Full hiragana and katakana each contribute one mora.
Small ゃゅょ (and katakana ャュョ, plus small ぁぃぅぇぉ) merge with the preceding kana and add nothing.
ん, っ, and ー each stand as their own mora.
Punctuation, spaces, kanji, and Latin characters are ignored.

Why morae and syllables differ

The mora is the fundamental rhythmic unit in Japanese, and it does not map one-to-one onto English syllables. Two key differences catch writers by surprise:

Long vowels add a mora. The word コーヒー (kōhī, coffee) has four morae — コ, ー, ヒ, ー — even though most English speakers hear it as two syllables. Similarly, とうきょう (Tōkyō) is four morae: とうきょう → と, う, きょ, う.

ん counts independently. The syllabic nasal ん is its own mora. にほん (Nihon, Japan) is four morae: に, ほ, ん — three characters but four beats because ん stands alone.

This is why a Japanese haiku translated into English and kept to “5-7-5 syllables” does not reproduce the original rhythm. The tools are measuring different things.

Worked examples

Phrase	Breakdown	Morae
ふるいけや	ふるいけや	5
かわずとびこむ	かわずとびこむ	7
みずのおと	みずのおと	5
きょう	きょ + う	2
しんぶん	し + ん + ぶ + ん	4
コーヒー	コ + ー + ヒ + ー	4

The classic Bashō haiku 古池や蛙飛び込む水の音 has 5-7-5 morae when written in kana, confirming the 5-7-5 structure.

Note on kanji input

The counter only processes kana. If your poem is written with kanji, convert each word to its kana reading first — you can type the kana reading in parentheses beside the kanji, then remove the kanji before counting. The tool ignores kanji and will undercount if they are left in. Everything runs in your browser.