Now that China has surpassed Japan to become the world’s second-largest economy, economists predict it’s on track to replace the US as the world’s biggest by 2025. But what does the higher rank really mean for the average Chinese citizen?

There is no doubt China has achieved impressive growth over the past decade. But even though the country has averaged about 10% growth over the past several years, that doesn’t mean the average Chinese citizen is necessarily eating or sleeping better than the average German or Frenchman. In fact, with GDP per capita at $3,744 in 2009, China placed #86 out of 164 countries ranked according to 2009 World Bank data. This was just below much smaller economies such as Tunisia, Albania and Jordan.

While Japan might have lost its place to China, the average citizen there is still generally much richer. In 2009, Japan’s GDP per capita, at $39,727, ranked it 19. What’s more, even while the size of the U.S. economy ranks just one notch above China’s, it’s nevertheless one of the richest countries in the world with GDP per capita in 2009 at $45,989. In 2010, Japan’s GDP per capita rose to $42,500 while in the U.S. it rose to $47,100.

Even while China’s population is still poor relative to most developed countries, many of its citizens must be feeling flush with wealth. Its GDP per capita surged from just $3,744 in 2009 to $4,300 in 2010, according to the CIA Factbook, a 15% jump.

There is little doubt that China’s economy will eventually surpass the U.S., mostly because of its sheer size — its population is 1.3 billion, versus just 300 million in the U.S. Starting in 2000, China’s economy began its aggressive climb through the top ten economies, surpassing many of the world’s most advanced economies. In 2000, it bumped Italy to become the sixth-biggest economy in the world. Five years later, China unseated France, rising its way to be the fifth-largest economy. Then in 2006, it trumped the United Kingdom, then Germany the next year.

China stayed in third place for the next three years until 2010. It was the year when Japan’s economy – hampered by weak demand and a rapidly aging population – contracted by 0.3% during the fourth quarter, marking the first time in five quarters that its economy has ever contracted.