Translation guide
The English word "sufficient" expresses that something is enough to meet a need or requirement. In Japanese, this concept is most commonly expressed with the adjective 十分 (じゅうぶん), but other words and patterns are used depending on formality, context, and whether the focus is on quantity, quality, or condition.
Expressing that an amount, number, or degree is adequate for a purpose.
The most common and versatile word for "sufficient" or "enough." Can be used as a na-adjective or adverb. Works in both spoken and written Japanese.
お金は十分あります。
I have sufficient money.
十分な量の水を用意してください。
Please prepare a sufficient amount of water.
A verb meaning "to be enough" or "to suffice." Often used in negative form to indicate insufficiency. More colloquial than 十分.
Alternative kanji for 十分, often used in formal writing. Meaning is identical, but 充分 can emphasize "fully" or "amply."
充分な検討が必要だ。
Sufficient consideration is necessary.
Indicating that conditions, qualifications, or criteria are satisfied.
Again the default choice. Can modify nouns or verbs to show that something meets a standard.
彼の説明は十分だった。
His explanation was sufficient.
この書類だけで十分ですか？
Is this document alone sufficient?
Pattern meaning "just ~ is enough." Useful for emphasizing that nothing more is needed.
メールだけで十分です。
An email alone is sufficient.
Literary/formal verb meaning "to suffice." Rare in modern conversation, but appears in set phrases and formal writing.
彼は信頼するに足る人物だ。
He is a person worthy of trust (sufficient to trust).
Describing a state where no external support is needed.
Specifically means "self-sufficient," often in economic or survival contexts.
その村は食料を自給自足している。
The village is self-sufficient in food.
Means "sufficient by oneself" or "I can manage alone." Used when refusing help.
手伝いは要りません。一人で十分です。
I don't need help. I'm sufficient on my own.
In formal logic, a condition that guarantees the outcome.
The technical term for "sufficient condition." Used in mathematics, logic, and formal reasoning.
それは十分条件だが、必要条件ではない。
That is a sufficient condition, but not a necessary condition.
十分 is an adjective/adverb and sounds more objective or formal. 足りる is a verb and is more common in casual speech, especially in negative forms like 足りない (not enough). Use 十分 for general statements of sufficiency; use 足りる when focusing on whether a specific amount meets a need.
English often uses 'sufficient' before a noun (e.g., 'sufficient funds'). In Japanese, 十分な + noun is natural, but in many cases a simpler expression like 足りる or 大丈夫 is more idiomatic. Overusing 十分な can sound stiff.
この量で十分ですか？
Is this amount sufficient?
十分な証拠があります。
We have sufficient evidence.
簡単なお礼で十分です。
A simple thank-you is sufficient.