$12.50 is the $ value per tick.
.000001 is the tick size.
So, a contract move of .000001 = $12.50
$12.50 / .000001 = $12,500,000
$12,500,000 * .00015 (your example option premium) is?
...
On ES,
$12.50 is the $ value per tick
.25 is the tick size
So, a contract move of .25 =...