Yep, esmi said right. You would need to use a theme that offers custom logo functionality OR if you’re using Twenty Eleven Theme then user below technique:
#1. Login to your Dashboard.
#2.Click Apperance -> Editor
#3. Open header.php file and check for below line
<?php bloginfo( 'name' ); ?>
#4. delete the particular code ( exactly above one ) and replace it with the below code.
<img src="https://yoursite.com/logo.png" alt="your site name" width="200" height="35"/>
#5. Now you have to remove the description that comes along with your logo. For this just remove the below code.
<?php bloginfo( 'description' ); ?>
#6. Last step upload your logo to your home folder and name it as logo.png, if you are uploading some where or if you have any other dimensions for your logo update code at point4 ( #4 ).
if the problem continuous go to Dashboard->Apperance->Editor->Style.css and check for below part of code:
#branding img {
height: auto;
margin-bottom: -7px;
width: 100%;
}
and remove width:100%
OR
Click here and see video: https://www.youtube.com/watch?v=tLp0Ig6l1t0
