I used the calculator to calculate the CTS using 1.5 knots of current from 135 degrees Magnetic and a boat speed of 6 knots and it replied with a CTS of 10.78 degrees towards the current.
Firstly there isn't a helmsman that ever lived that could steer to 2 decimals of a degree and secondly, if you're going to offer to calculate a CTS then why not answer with a CTS and not with the angle you need to subtract from the widget and divide by the length of you whatsit to get to where your heading should be.
I never even bothered looking at the second calculator.
Sorry, not picking on anybody but geez . . . . .