Show "You Save" Amount on Sale Products

add_filter( 'woocommerce_get_price_html', function ( $html, $product ) {
    if ( is_admin() || ! $product instanceof WC_Product || ! $product->is_on_sale() || $product->is_type( array( 'variable', 'grouped' ) ) ) {
        return $html;
    }

    $regular = (float) wc_get_price_to_display( $product, array( 'price' => $product->get_regular_price() ) );
    $sale    = (float) wc_get_price_to_display( $product, array( 'price' => $product->get_sale_price() ) );

    if ( $regular <= 0 || $sale >= $regular ) {
        return $html;
    }

    $saving  = $regular - $sale;
    $percent = round( $saving / $regular * 100 );

    return $html . sprintf( '<span class="wpide-you-save" style="display:block;font-size:.85em;color:#008a20;">You save %s (%d%%)</span>', wc_price( $saving ), $percent );
}, 20, 2 );

add_filter( 'woocommerce_available_variation', function ( $data, $parent, $variation ) {
    if ( $variation->is_on_sale() && (float) $data['display_regular_price'] > (float) $data['display_price'] ) {
        $saving             = (float) $data['display_regular_price'] - (float) $data['display_price'];
        $data['price_html'] .= sprintf( '<span class="wpide-you-save" style="display:block;font-size:.85em;color:#008a20;">You save %s</span>', wc_price( $saving ) );
    }

    return $data;
}, 10, 3 );