When standing on a beach how many miles is the horizon looking out at sea?

The distance to the horizon when standing on a beach can be approximated using the formula ( \sqrt{1.5 \times h} ), where ( h ) is your height in feet. For an average adult standing at about 5.5 feet tall, the horizon would be roughly 2.5 miles away. This distance increases with height; for instance, if you were on a higher vantage point, like a cliff, the horizon would be further away.