Dating the exodus
The way it is written in the Hebrew implies that it is intended to be a precise figure (see Cassuto (1961, 52)) .
The date also correlates with the length of Israel’s period of Judges (Young and Wood 2008), with Jephthah’s argument in Judges , and with the Jewish Sabbatical and Jubilee calendar (Young 2003).
Interestingly, the Greek Septuagint Bible gives 440 years in this verse.
| | H for Historical 'fit' from Joseph forward, #1: Hatshepsut's Barren Dilemma | | Chrono, H#2-4, backgrounder on Israel in Egypt | | H#5-6, Hat's Solution | | H#7-10, Hat's Precedenting Usurpation (using Moses) | | H#11-12, Moses under Hat thru her death | | H#13-15, Moses abdicates |  | H#16-17, 'other' Thutmose III comes to power |  | H#18-21, Amenhotep II | | H#22-end, Aftermath (decline of Egypt) | Apologies up front: the first few sections of this webpage are decidedly acerbic, for which I apologize.
So maybe just skim the content until you get to "Historical 'fit'" intra-page link #H, which takes you through the history from Joseph's time, forward. Since the Exodus is the basis for the entire existence of the Bible, and the Bible spends every verse tying TO the Exodus, you'd think the people trying to date the Exodus would actually consult the Bible itself, to know the date. What has happened instead, is a lot of tail-chasing after artifacts.
The last chapter will focus on the archaeological evidence that has been found that best fits into the chronology of the Exodus.
The most important discovery is the Merneptah stele that mentions Israel which forced the revision of a number of liberal theories.For a synopsis on how God's Accounting System works in BIBLE, click here for brainout #6a.