顺理成章

shùn lǐ chéng zhāng

to follow naturally; the logical next step

Character by character

顺shùn
follow

理lǐ
logic

成chéng
form

章zhāng
chapter

两人在一起五年了，结婚是顺理成章的事。

They'd been together five years; marriage was the natural next step.

Tone: neutral.

Originally well-structured writing; now any natural outcome.

Learn it in context

This idiom and thousands more are in Learn Chinese with Bao, with audio, pinyin and drills that make them stick.