In the input field you can use any of the formats shown in the results section below.
If you use N/S/E/W it must come last. Alternatively, you can use a minus sign before the degree value.
Alternatively, you can populate the two fields with your approximate current location using the button provided (if your browser supports geolocation). Note that (a) it takes a moment to locate you, and (b) the result is only an approximation to your current location.