You're talking to an American. They use anything but a logical system. To explain to them what a kilometer is, you need to put yourself in their position and go from that. Let me help:

A kilometer is:

• ~167 Ford F-150's,
• ~1,150 dishwashers,
• ~5,556 bibles,
• ~5,263 bananas,
• ~1,250 AR-15's,
• ~0.62 miles,
• ~3,281 feet,
• ~39,370 inches,
• etc.

To make sense to an American, you need to not make any sense. This includes swapping the period and comma around in numbers, but you already did that.