Hopes

78 years

This scenario assumes that both the billion-person economies grow in line with the best official projections.

That would see China growing 7% this year and India growing as much as 8.5% in the fiscal year starting next month.

It also involves the unlikely case that both economies will continue to grow at those rates on average long into the future.

All that being the case, India will pass China in terms of size around 2093. That’s 78 years from now.

Dreams

23 years

Let’s dream bigger, though. If you assume that India was at last able to push its gross domestic product expansion up to an average of 10% a year and meanwhile China’s mature economy settled down to an average of around 5% a year, then it would only take 23 years for the South Asian nation to overtake its eastern rival.

Nightmares

11 years

Let’s assume China’s slowdown is even worse. Even if it stopped growing altogether and India was still somehow able to expand at 10% a year on average, it would take more than a decade for India to reach China’s GDP total of around $10 trillion. Of course, having one of the worlds’ biggest economies just stop growing for decades would be a catastrophe that would change growth everywhere so this scenario, like the others, is basically just a mathematical trick.

Generations

3

So, how long is the 78 years it would take India to catch up at the current rate of growth? About three generations. That is to say that India will not become bigger than China until after your great-grandchildren are born.

Another Era

1937

Another way to get perspective on how long that is: think back 78 years, to 1937. That was the year George IV was crowned king of the British Empire and emperor of India. Toyota Motor Corp. was founded in August that year. Hitler wouldn’t invade Poland for another two years.