Live Demo: Bootstrap 4 Progress Bar Height Sizing

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Bootstrap 4 Progress Bar Height Sizing</title>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@4.6.0/dist/css/bootstrap.min.css">
<script src="https://code.jquery.com/jquery-3.5.1.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/bootstrap@4.6.0/dist/js/bootstrap.bundle.min.js"></script>
<style>
    .bs-example{
        margin: 20px;        
    }
    /* Adding space at the bottom of progress bar */
    .progress{
        margin-bottom: 1rem;
    }
</style>
</head>
<body>
<div class="bs-example">
    
    <div class="progress" style="height: 1px;">
        <div class="progress-bar" style="width: 50%;"></div>
    </div>
    
    <div class="progress" style="height: 20px;">
        <div class="progress-bar" style="width: 50%;"></div>
    </div>
</div>
</body>
</html>