Вы можете использовать SVG в качестве фона, и вы сможете легко контролировать размер:
.rating {
background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" width="68" height="11" viewBox="0 0 68 11"><path fill="grey" d="M6 8.84L9.708 11l-.984-4.07L12 4.192l-4.314-.354L6 0 4.314 3.838 0 4.192 3.276 6.93 2.292 11zM20 8.84L23.708 11l-.984-4.07L26 4.192l-4.314-.354L20 0l-1.686 3.838L14 4.192l3.276 2.738-.984 4.07zM34 8.84L37.708 11l-.984-4.07L40 4.192l-4.314-.354L34 0l-1.686 3.838L28 4.192l3.276 2.738-.984 4.07zM48 8.84L51.708 11l-.984-4.07L54 4.192l-4.314-.354L48 0l-1.686 3.838L42 4.192l3.276 2.738-.984 4.07zM62 8.84L65.708 11l-.984-4.07L68 4.192l-4.314-.354L62 0l-1.686 3.838L56 4.192l3.276 2.738-.984 4.07z"/></svg>');
width: 68px;
height: 11px;
}
.rating:before {
content: "";
display: block;
background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" width="68" height="11" viewBox="0 0 68 11"><path fill="tomato" d="M6 8.84L9.708 11l-.984-4.07L12 4.192l-4.314-.354L6 0 4.314 3.838 0 4.192 3.276 6.93 2.292 11zM20 8.84L23.708 11l-.984-4.07L26 4.192l-4.314-.354L20 0l-1.686 3.838L14 4.192l3.276 2.738-.984 4.07zM34 8.84L37.708 11l-.984-4.07L40 4.192l-4.314-.354L34 0l-1.686 3.838L28 4.192l3.276 2.738-.984 4.07zM48 8.84L51.708 11l-.984-4.07L54 4.192l-4.314-.354L48 0l-1.686 3.838L42 4.192l3.276 2.738-.984 4.07zM62 8.84L65.708 11l-.984-4.07L68 4.192l-4.314-.354L62 0l-1.686 3.838L56 4.192l3.276 2.738-.984 4.07z"/></svg>');
height: 100%;
width: var(--p, 50%);
}
<div class="rating"></div>
<div class="rating" style="--p:20%"></div>
<div class="rating" style="--p:80%"></div>
<div class="rating" style="--p:100%"></div>
Для лучшей поддержки вы можете заменить переменную CSS классическим CSS:
.rating {
background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" width="68" height="11" viewBox="0 0 68 11"><path fill="grey" d="M6 8.84L9.708 11l-.984-4.07L12 4.192l-4.314-.354L6 0 4.314 3.838 0 4.192 3.276 6.93 2.292 11zM20 8.84L23.708 11l-.984-4.07L26 4.192l-4.314-.354L20 0l-1.686 3.838L14 4.192l3.276 2.738-.984 4.07zM34 8.84L37.708 11l-.984-4.07L40 4.192l-4.314-.354L34 0l-1.686 3.838L28 4.192l3.276 2.738-.984 4.07zM48 8.84L51.708 11l-.984-4.07L54 4.192l-4.314-.354L48 0l-1.686 3.838L42 4.192l3.276 2.738-.984 4.07zM62 8.84L65.708 11l-.984-4.07L68 4.192l-4.314-.354L62 0l-1.686 3.838L56 4.192l3.276 2.738-.984 4.07z"/></svg>');
width: 68px;
height: 11px;
}
.rating > div {
background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" width="68" height="11" viewBox="0 0 68 11"><path fill="tomato" d="M6 8.84L9.708 11l-.984-4.07L12 4.192l-4.314-.354L6 0 4.314 3.838 0 4.192 3.276 6.93 2.292 11zM20 8.84L23.708 11l-.984-4.07L26 4.192l-4.314-.354L20 0l-1.686 3.838L14 4.192l3.276 2.738-.984 4.07zM34 8.84L37.708 11l-.984-4.07L40 4.192l-4.314-.354L34 0l-1.686 3.838L28 4.192l3.276 2.738-.984 4.07zM48 8.84L51.708 11l-.984-4.07L54 4.192l-4.314-.354L48 0l-1.686 3.838L42 4.192l3.276 2.738-.984 4.07zM62 8.84L65.708 11l-.984-4.07L68 4.192l-4.314-.354L62 0l-1.686 3.838L56 4.192l3.276 2.738-.984 4.07z"/></svg>');
height: 100%;
width:50%;
}
<div class="rating"></div>
<div class="rating" ><div style="width:20%"></div></div>
<div class="rating" ><div style="width:80%"></div></div>
<div class="rating" ><div style="width:100%"></div></div>