Adjust the quantity input values

Woocommerce: woocommerce.php

<?php
/**
 * Adjust the quantity input values
 */
function pixelplus_woocommerce_quantity_input_args( $args, $product ) {
	$args['step'] = '0.01';
	return $args;
}
add_filter( 'woocommerce_quantity_input_args', 'pixelplus_woocommerce_quantity_input_args', 10, 2 );

remove_filter( 'woocommerce_stock_amount', 'intval' );
add_filter( 'woocommerce_stock_amount', 'floatval' );

function pixelplus_unit_price_fix( $price, $order, $item, $inc_tax = false, $round = true ) {
	$qty = ( ! empty( $item['qty'] ) && $item['qty'] != 0 ) ? $item['qty'] : 1;
	if ( $inc_tax ) {
		$price = ( $item['line_total'] + $item['line_tax'] ) / $qty;
	} else {
		$price = $item['line_total'] / $qty;
	}

	$price = $round ? round( $price, 2 ) : $price;
	return $price;
}
add_filter( 'woocommerce_order_amount_item_total', 'pixelplus_unit_price_fix', 10, 5 );