How do I find my header size now I adjusted the header menu bar?

Hi all,

Brand new to all this, and I may be starting a thread that is already done, but I can’t find it anywhere… anywhere at all! 🙁

I have recently changed the header of my blog using this code for custom CSS:

.navbar > .container .navbar-brand {
margin-top: 25px;
}

works perfectly, but when I go to change my header image it still says the recommended size is 76×300 px, and to create a new larger header I need to know how big to make it in Photoshop so that; 1: It’s more in keeping with the size of the menu bar and 2: my logo will actually be a size that people can see.

My blog is http://fiveyeartarget.com if you want to take a look yourself.

The code also doesn’t tell me anything about size as far as I can tell…

Thank you in advance.

Jack