Infographic: The 20 largest economies in the world by GDP.

Since 2014, China has maintained its position as the largest economy by production volume adjusted for PPP. The United States ranks second, trailing China by approximately four trillion dollars in this metric.

India occupies the third spot, with its GDP adjusted for PPP being nearly four times greater than its nominal GDP. Rounding out the top five are Russia and Japan.

How is PPP calculated and why?

A country's GDP is converted into a common currency using exchange rates that account for differences in price levels between nations. This ensures that the same basket of goods and services has an equal value across all countries, reflecting the true economic output.

The advantage of this method is that it considers the relative strength of countries with low and middle income levels, as their costs are lower than those of high-income countries.

This is why India's GDP, adjusted for PPP, is significantly higher than its nominal GDP.