How Did 70 People Become 2 Million? A Surprising Look at the Numbers Behind Israel’s Growth in Egypt

Some critics have long questioned the Bible’s account of the Israelites growing from just 70 people to over 2 million in about 300 years. They argue that such a huge increase seems unrealistic without some kind of exaggeration.

For instance, Colin J. Humphreys considers this “grossly unrealistic,"[1]

But what if it’s not unrealistic at all?

What if the Bible’s numbers actually make sense — even under normal biological conditions?

Let’s take a closer look.

The Big Question

According to the Bible, Jacob and his family — 70 people in all — went down to Egypt (Genesis 46:27). Around 300 years later, when Moses led the Israelites out of Egypt, the Bible says there were about 600,000 men, not counting women and children (Exodus 12:37). That would mean a total population of 2 million or more.

How could that happen in just 12 generations?

The Realistic Model

To answer this, we used a population growth model based on real-world numbers, not miracles. Here are the assumptionswe used:

• Average family size: 8 children per couple

• Infant/child survival: 70% live to adulthood

• Reproductive adults: 75% of adults go on to have children

• Average lifespan: about 100 years (4 overlapping generations)

• Time per generation: 25 years

• Total time: 300 years (about 12 generations)

• Starting population: 70 people

Running the numbers under these conditions produces a total population of only about 9,000 people by the end of 300 years — far short of the Bible’s claim.

What’s Missing?

It turns out the natural birth rate, even under good conditions, can’t fully explain the growth. But then we tested one simple factor:

What if just a small number of people joined the Israelites in each generation?

When you add a tiny growth factor to the model — a mix of intermarriage (Israelites marrying Egyptians or others) and migration (others joining the Israelite group) watch what happens.

I wanted to find the smallest amount of outside growth needed to reach 2 million people in 300 years.

The Surprising Answer

To reach 2 million people in 300 years under this model, all it would take is:

An outside growth rate of just 0.21% per year,or about 2.1% per generation.

That’s it!

If, in each generation, just 2 out of every 100 Israelites brought in a spouse or friend from outside their group — or if just a small number of outsiders were absorbed into their community — the total population could grow to 2 million naturally.

Let’s Put That in Perspective

Here’s a rough breakdown of population growth over 300 years using this model:

Year Approx. Population

0 70

50 ~280

100 ~1,100

150 ~4,300

200 ~17,000

250 ~67,000

300 ~2,000,000

All with moderate birth rates, normal death rates, and a tiny intermarriage/migration rate.

So, What Does This Mean?

It means that the biblical account is not as far-fetched as it might seem. You don’t need to imagine miracle births or inflated numbers. Just steady family growth, good survival rates, and a small but consistent stream of outsiders joining the Israelites.

In fact, the Bible itself says, “the Israelites were fruitful and multiplied greatly” (Exodus 1:7). And later, when they left Egypt, we’re told a “mixed multitude” went with them (Exodus 12:38) — hinting at this very idea of people joining their community along the way.

The Takeaway

Sometimes, what sounds impossible at first becomes entirely reasonable when you dig into the details. Critics may scoff at 70 people growing into a nation, but the math — and the history — tell a different story.

A little growth, over a long time, goes a very long way.

Zipporah was the Midianite wife of Moses, the daughter of Jethro (also called Reuel), a priest of Midian (Exodus 2:16–21). She is portrayed as a wise, courageous, and resourceful woman. Though a foreigner, she plays a vital role in Moses’ life and even in preserving it.

Footnotes:

[1] Colin J. Humphreys, The Number of People in the Exodus from Egypt: Decoding Mathematically the Very Large Numbers in Numbers I and XXVI (2021), accessed May 15, 2025, https://www.academia.edu/75936314/The_Number_of_People_in_the_Exodus_from_Egypt_Decoding_Mathematically_the_Very_Large_Numbers_in_Numbers_I_and_XXVI.