Fit div size to background image - css

Question

I'm trying to set the size (both width and height) of a div to match it's background image size, but I can't get it working.
The background image size has to be in percentages, because I'm dealing with a responsive website. On smaller screens, the background should be displayed completely (with less width, but still proportional), and the div who has the image should follow that size.
I tried various values of the background-size, such as auto 100%, cover, contain, etc. but nothing did the trick.
There's a similar question here about this: scale div to background image size but it didn't solve my problem either.
I'd really appreciate if someone knows how to do it.
EDIT:
I made a fiddle to show the behavior: http://jsfiddle.net/osv1v9re/5/
This line is what is making the background image so small:
background-size: auto 100%;
But if it is removed is removed, the background will fill the proper width, but not the height.

Answer 1

tag cannot adapt to background-image size, you need to use an tag and choose between height: auto for the div or javascript
// **** Problem ****
// Wrong html :
<div class="my_class"><div>
// with css :
.my_class {
width: 100%;
height: 100%;
background-image: url(/images/my-image.jpg);
background-size: 100%;
background-position: center;
background-repeat: no-repeat;
}
//**** Solution ****
// use css:
.my_class {
width: 100%;
height: 100%;
background-image: url(/images/my-image.jpg);
background-size: contain;
}

Answer 2

*{
padding: 0;
margin: 0;
}
div{
width: 100%;
}
div figure{
padding-top: 36.56%; /* 702px/1920px = 0.3656 */
display: block;
background: url("https://st.fl.ru/images/landing/bg2.jpg") no-repeat center top;
background-size: cover;
}
<div>
<figure></figure>
</div>

Answer 3

you can have a responsive height using the padding-bottom or padding-top
because you can't fix an height property in '%' with a width in '%'.
div{
background-image: url(url);
background-repeat: no-repeat;
background-size: 100% 100%;
background-position: center;
margin: 0 auto;
width: 100%;
padding-bottom: heightPicure / widthPicture + %; //do it manually or using scss rules
}