150 AD is in the second century, which spans the years 101-200.
430
The first century AD
The sixth century AD covers the years from 501 AD to 600 AD.
-99
If you let BC years be negative then it could be the difference between -150 and 200 which is 200 - -150 = 350. However, as there was NO year 0 (as zero did not come to Europe until around the 11th-12th centuries and Dionysius Exiguus ("Little Dennis") created the AD/BC system of dates in 247 Anno Diocletani, calculating Jesus' birth to be 531 years earlier and made it 1 AD, thus making his "current year" 532 AD; and explains why the 21st century AD did not start until 2001). Thus from 150 BC to 200 AD is one less at 349 years.
5th
1st century AD
The first century AD.
The 3rd Century AD.
It is the first century AD.
The 1st century AD.
The 1st century AD.
It is the first century AD.
The 1st century AD.
It is the second century AD.
The first century AD.
It is the 18th century AD.