👉 Around the time of Jesus Christ’s birth (roughly 4–1 BCE), the world population was about 170 million to 300 million people.

Breakdown (approximate):
Roman Empire: ~45–60 million
Han Dynasty China: ~55–75 million
India (various kingdoms): ~30–50 million
Rest of the world: smaller populations spread across Africa, Europe, the Americas, and elsewhere
Most commonly cited estimate:

➡️ ~200–250 million people worldwide

For perspective:

Today’s population is over 8 billion
So the world had less than 3% of today’s population