ということはIf that is so, that means...
ということは takes a fact or statement as the basis for an inference: “if that is so, then that means...” It introduces the conclusion, interpretation, calculation, or practical consequence that follows.
From premise to conclusion
The information before this expression is treated as accepted for the moment. The speaker then asks what follows from it or states the resulting interpretation. The final は makes “what that means” the topic, so the expression normally points forward to a conclusion. Here it is written は but pronounced わ.
A calculated consequence
来月から家賃が一万円上がるということは、年間で十二万円余計にかかる。
If the rent is going up by 10,000 yen next month, that means it will cost an extra 120,000 yen a year.
AnalyzeDrawing a conclusion in conversation
最終バスはもう出たよ。
The last bus has already left.
Analyzeってことは、歩いて帰るしかないね。
So that means we have no choice but to walk home.
AnalyzeThe casual contraction is natural here because the speakers are talking informally.
Interpretations and checks
The conclusion can be a firm deduction, a practical requirement, or a question checking whether the inference is correct.
期限が金曜日だということは、木曜日までに確認を終える必要がある。
If the deadline is Friday, that means we need to finish checking everything by Thursday.
Analyze予約が取れたということは、予定どおり出発できるんですね。
Since the reservation went through, that means we can leave as planned, right?
Analyze彼が会議に出ないということは、代理の人が来るんですか。
If he is not attending the meeting, does that mean someone will come in his place?
AnalyzeDo not confuse the setup with the conclusion
ということは foregrounds a premise and opens the reasoning that follows. Sentence-final ということだ instead reports information or closes an explanation. わけだ commonly presents the resulting realization itself rather than setting up the premise.
More examples
この電車が各駅に止まるということは、到着までかなり時間がかかりそうだ。
If this train stops at every station, it will probably take quite a while to arrive.
Analyze二人で半分ずつ払うということは、一人三千円ですね。
If the two of us each pay half, that means 3,000 yen per person.
Analyze彼が返事をしないということは、まだ決めていないのかもしれない。
The fact that he has not replied may mean that he has not decided yet.
Analyze会場が変更になったということは、案内も修正しなければならない。
If the venue has changed, that means the information notice also needs to be revised.
Analyze今日中に発送されたということは、明日には届く可能性がある。
Since it was shipped today, there is a chance it will arrive tomorrow.
Analyzeそれだけ詳しく説明できるということは、実際に使ったことがあるんですね。
If you can explain it in that much detail, you have actually used it before, right?
Analyze