In the third century B.C., Ptolomy II commissioned a priest named Manetho to compile a history of Egypt. Manetho did so. Then, in 1904, Eduard Meyer created the Sothic cycle in 1904 to give Egypt a unified calendar that aligns Egyptian regnal years with modern historians’ B.C. Dates.1 And these two sources, Manetho's history and Meyer's Sothic cycle, are the foundations of traditional dates for Egyptian history—traditional dates which contradict the time line found in the Biblical genealogies. For instance, if you take all of the Pharaohs mentioned by Manetho, and stack their rules together, you have the Pyramids being constructed well before the flood, and Egypt, as a nation, predating the 2242 B.C. date of the Tower of Babel.
But should the Pharaoh's rules be stacked one on top of another? Carbon dating2 and many Egyptologists say no. Professor J. H. Breasted, author of History of Egypt, called Manetho’s history “a late, careless and uncritical compilation, which can be proven wrong from the contemporary monuments in the vast majority of cases, where such documents have survived.”3 In fact, if other sources are compared with Manetho's history, as David Down when he compiled his revised chronology, not only do we find that Egypt was founded not long after the tower of Babel, but we also find evidence of the Hebrew slaves in Egypt, of Joseph's famine, and many other Biblical references.
So does (Manetho's) Egyptian chronology contradict the Bible? No, not unless you “stack” the pharaohs, and disregard nearly every other source.
If you are an Egyptologist yourself, I expect you will find this brief layman's explanation unsatisfactorily vague. For more information, try:
Unwrapping the Pharaohs: How Egyptian Archaeology Confirms the Biblical Timeline, by John Ashton, Master's Books (2006)
Or, if you are a layman looking for a more detailed explanation, you can find one here.
1D. Mackey, “Fall of the Sothic Theory: Egyptian Chronology Revisited,” TJ 17 no. 3 (2003): 70–73, available at www.answersingenesis.org/tj/v17/i3/sothic_theory.asp.
2Radiocarbon dating of artifacts from Egypt’s Pre-dynastic period and First Dynasty, Reported September 4th 2013 in the Proceedings of the Royal Society, by Michael Dee and colleagues.
3D. Mackey, “Sothic Star Dating.”