Write down the coordinates of the two endpoints. The x coordinate is listed first and then the y coordinate. For instance, you might have a point at (2, 3) and another at (6, 5).
Subtract the first x coordinate from the second x coordinate. In this example, you would subtract 2 from 6 to get 4.
Square your answer from Step 2. In this example, you would multiply 4 times 4 to get 16.
Subtract the first y coordinate from the second y coordinate. In this example, you would subtract 3 from 5 to get 2.
Square your answer from Step 4 and add it to your squared answer from Step 3. In this example, you would square 2 to get 4 and add 4 to 16 to get 20.
Take the square root of your answer from Step 5 to find the distance between the two points. In this instance, you would take the square root of 20 to get a distance of 4.472.