<style>
  .result {
    font-size: 24px;
    font-weight: 700px;
    font-family: sans-serif;
  }
</style>
<input type="range" min="0" max="100" value="0" id="range">
<div class="result">0%</div>

range.oninput = function () {
  document.querySelector(".result").innerHTML = this.value + "%";
};