To have been decided or arranged that; to be scheduled or determined (often used at the end of a sentence to report a decision or arrangement).
来月から部署が変わることになりました。
It has been decided that I'll be transferred to a different department starting next month.
会議は明日の午後3時に行うことになっています。
The meeting is scheduled to be held tomorrow at 3 PM.
両親の反対で結婚は延期することになった。
Because of my parents' opposition, it was decided to postpone the wedding.
To be the result or outcome of something; used to state what naturally follows as a consequence.
毎日練習した結果、試合に勝つことになった。
As a result of practicing every day, we ended up winning the match.
彼は長時間働いたので、疲労がたまり病気になることになった。
Because he worked long hours, his fatigue built up and he ended up getting sick.
価格の上昇により、売上が減ることになった。
Due to the price increase, sales ended up decreasing.
Used (somewhat formal/written) to indicate that one thing becomes the reason or cause for something else (in everyday speech, phrases like '理由になる' or '原因になる' are more common).
彼の失言がトラブルの原因になることになった。
His inappropriate remark ended up becoming the cause of the trouble.
設備の故障が納期遅れの理由になることになった。
The equipment failure turned out to be the reason for the delivery delay.