This calculator can be used to return a number of how many players (numbers, not names) have earned a particular trophy. For instance, the platinum trophy for Fallout: New Vegas reads that 1.1% of players have earned it, this calculator will provide you with an exact number based on the total number of active PlayStation gamers. So the answer for 1.1% is 1,375,000 - that's how many players have earned the trophy.
125 million is the base number for the calculator.