There appear to be differing accounts about how tall Goliath was.
The 1st century historian Josephus, and both The Dead Sea Scrolls texts and 4th century Septuagint texts of Samuel report Goliath as being "four cubits and a span" (6 feet 9 inches or 2.06 metres). This differs somewhat (3 feet, to be precise) from the the Masoretic Text of Samuel, which claims his height as "six cubits and a span" (9 feet 9 inches or 2.97 metres).
Are there any sources in the Talmud or Midrash that provide a conclusive height?