No — but it helps at advanced levels.
All core concepts (Yin-Yang, Five Elements, Stems, Branches, 10 Gods) can be learned in English. The logic is universal. Many Westerners become competent BaZi readers without Chinese literacy.
What you may miss without Chinese:
- Nuanced wordplay in classical texts
- Cultural context for certain symbolic associations
- Access to untranslated advanced materials
But for practical, personal-use BaZi, English resources are more than sufficient. The system is mathematical and logical at its core — it translates well. Start where you are. If the passion deepens, Chinese language study can follow.