<section class="example width-400px">
  <div class="cropped-image"></div>
</section>
<section class="example width-600px">
  <div class="cropped-image"></div>
</section>
<section class="example width-800px">
  <div class="cropped-image"></div>
</section>

:root {
  font-family: sans-serif;
}

*,
*:before,
*:after {
  box-sizing: border-box;
}

.example {
  height: 150px;
}

.width-400px {
  width: 400px;
}

.width-600px {
  width: 600px;
}

.width-800px {
  width: 800px;
}

.cropped-image {
  width: 100%;

  aspect-ratio: 20 / 3;

  background-image: url(https://ucarecdn.com/bf4880fc-dcf3-445f-8f9a-892e2df8ec45/-/preview/1200x800/);
  background-position: center 32.5%;
  background-repeat: no-repeat;
  background-size: cover;
}