。
Calculate how much money you'll need next year.
Literal
Next-year [topic-は] how-much money [subject-が] need [question-か] calculate-do.
いる here is 要る ('to need / require'), usually written in kana to avoid confusion with the homophone いる ('to exist'). The embedded question いるか ('how much is needed') is the object of 計算する — Japanese packs the question inside the main clause directly, no 'whether' needed.