Min and Max Quantity by Stock for WooCommerce: Step-by-Step Guide for WordPress
Managing product Min and Max Quantity by Stock in WooCommerce can be tricky, especially when dealing with stock limitations. Customers often try to add more products to their cart than you have in stock, or you may want to enforce specific quantity steps. In this tutorial, we’ll show you how to implement Min and Max Quantity by Stock in WooCommerce, fully compatible with the Woodmart theme, with automatic adjustments and AJAX-friendly behavior.
Why Set Min and Max Quantity by Stock in WooCommerce?
- Prevent overselling: Automatically limit the number of products customers can add to their cart based on stock.
- Encourage bulk purchasing: Use quantity steps for products that are sold in packs or sets.
- Smooth UX: Hide or disable quantity buttons when maximum stock is reached, making it easy for users to shop without errors.
- AJAX-friendly: Works seamlessly with Woodmart’s dynamic mini-cart and cart updates.
Universal Min/Max Quantity by Stock for WooCommerce
Automatically set min, max, and step values based on product stock, validate cart quantities, and disable the plus button when stock is reached. Works on any theme with AJAX updates.
// Set min/max quantity based on stock
add_filter('woocommerce_quantity_input_args', function($args, $product){
$stock = $product->get_stock_quantity();
$cart_qty = 0;
foreach (WC()->cart->get_cart() as $item){
if($item['product_id'] == $product->get_id()) $cart_qty = $item['quantity'];
}
if($stock>=2){ $args = ['min_value'=>2,'max_value'=>$stock,'step'=>2,'input_value'=>$cart_qty?:2]; }
elseif($stock==1){ $args = ['min_value'=>1,'max_value'=>1,'step'=>1,'input_value'=>1]; }
return $args;
}, 10, 2);
// Disable plus button when stock limit reached
add_action('wp_footer', function(){ ?>
<script>
jQuery(function($){
function disablePlus(){ $('.woocommerce-cart .cart_item, .woocommerce-mini-cart .mini_cart_item').each(function(){
var $i=$(this).find('input.qty'),$p=$(this).find('.plus,input.plus');
if($i.length && $p.length){ var q=parseInt($i.val(),10),m=parseInt($i.attr('max'),10);
if(!isNaN(m) && q>=m){ $p.prop('disabled',true); $i.prop('readonly',true); } else { $p.prop('disabled',false); $i.prop('readonly',false); }
}
}); }
disablePlus();
$(document.body).on('updated_wc_div updated_cart_totals wc_fragments_refreshed', disablePlus);
setInterval(disablePlus,2000);
});
</script>
<?php });
Benefits:
- Auto min/max & step values
- Cart validation & auto adjustment
- Works on all themes with AJAX
- Plus button disabled when stock reached
Full Code for WooCommerce Min/Max Quantity by Stock for Woodmart
Here’s the complete PHP and JavaScript code for your child theme functions.php:
/**
* ==============================================
* Custom Min/Max Quantity Rules (Woodmart Ready)
* Author: Md Mamun Miah / Webzlo
* ==============================================
*/
/**
* Set min/max quantity rules per product
*/
add_filter('woocommerce_quantity_input_args', 'webzlo_min_max_quantity_rules', 10, 2);
function webzlo_min_max_quantity_rules($args, $product) {
$stock = $product->get_stock_quantity();
// Get current cart quantity for this product
$cart_qty = 0;
foreach (WC()->cart->get_cart() as $cart_item) {
if ($cart_item['product_id'] == $product->get_id()) {
$cart_qty = $cart_item['quantity'];
break;
}
}
if ($stock >= 2) {
$args['min_value'] = 2;
$args['max_value'] = $stock;
$args['step'] = 2;
$args['input_value'] = $cart_qty > 0 ? $cart_qty : 2;
} elseif ($stock == 1) {
$args['min_value'] = 1;
$args['max_value'] = 1;
$args['step'] = 1;
$args['input_value'] = 1;
}
return $args;
}
/**
* Validate cart quantities
*/
add_action('woocommerce_check_cart_items', 'webzlo_validate_cart_quantity');
function webzlo_validate_cart_quantity() {
foreach (WC()->cart->get_cart() as $cart_item_key => $cart_item) {
$product = $cart_item['data'];
$stock = $product->get_stock_quantity();
$qty = $cart_item['quantity'];
if ($stock >= 2) {
$max_allowed = $stock;
if ($qty < 2 || $qty > $max_allowed || $qty % 2 != 0) {
wc_add_notice(sprintf(
__('The quantity for "%s" must be in steps of 2 and cannot exceed available stock (%d).', 'woocommerce'),
$product->get_name(),
$stock
), 'error');
}
} elseif ($stock == 1 && $qty != 1) {
wc_add_notice(sprintf(
__('The quantity for "%s" must be exactly 1.', 'woocommerce'),
$product->get_name()
), 'error');
}
}
}
/**
* Adjust cart quantities automatically
*/
add_action('woocommerce_before_calculate_totals', 'webzlo_adjust_cart_quantities');
function webzlo_adjust_cart_quantities($cart) {
if (is_admin() && !defined('DOING_AJAX')) return;
foreach ($cart->get_cart() as $cart_item_key => $cart_item) {
$product = $cart_item['data'];
$stock = $product->get_stock_quantity();
$qty = $cart_item['quantity'];
if ($stock >= 2) {
$step = 2;
$max_allowed = $stock;
$new_qty = floor($qty / $step) * $step;
if ($new_qty < 2) $new_qty = 2;
if ($new_qty > $max_allowed) $new_qty = $max_allowed;
if ($qty !== $new_qty) {
$cart->set_quantity($cart_item_key, $new_qty);
}
} elseif ($stock == 1 && $qty != 1) {
$cart->set_quantity($cart_item_key, 1);
}
}
}
/**
* For Woodmart theme AJAX Re-bind JS for Quantity Step + Stock Handling
*/
add_action('wp_footer', 'webzlo_woodmart_disable_plus_stock');
function webzlo_woodmart_disable_plus_stock() {
?>
<script type="text/javascript">
jQuery(document).ready(function($){
function disablePlusButtonsWoodmart() {
// Handle mini-cart and cart page
$('.woocommerce-mini-cart .mini_cart_item, .woocommerce-cart .cart_item').each(function(){
var $item = $(this);
var $qtyInput = $item.find('input.qty');
var $plusBtn = $item.find('input.plus');
if($qtyInput.length && $plusBtn.length){
var qty = parseInt($qtyInput.val(), 10);
var max = parseInt($qtyInput.attr('max'), 10);
if(!isNaN(max) && qty >= max){
$plusBtn.prop('disabled', true).addClass('disabled');
$qtyInput.prop('readonly', true);
} else {
$plusBtn.prop('disabled', false).removeClass('disabled');
$qtyInput.prop('readonly', false);
}
}
});
}
// Initial run
disablePlusButtonsWoodmart();
// Run after Woodmart AJAX updates
$(document).on('woodmart-ajax-loaded woodmartUpdateCart woodmartThemeModuleReinit', function(){
disablePlusButtonsWoodmart();
});
// WooCommerce AJAX fragments refresh
$(document.body).on('wc_fragments_refreshed updated_wc_div updated_cart_totals', function(){
disablePlusButtonsWoodmart();
});
// Optional fallback: check periodically
setInterval(disablePlusButtonsWoodmart, 2000);
});
</script>
<?php
}
How This Code Works
- Dynamic Min/Max Quantity:
Setsmin_value,max_value, andstepautomatically based on stock quantity. Products can have step increments (e.g., packs of 2) or single units if stock = 1. - Validation:
Prevents users from adding quantities that exceed stock or break step rules. - Automatic Adjustment:
If users manually enter wrong quantities, the cart auto-adjusts to valid quantities. - Woodmart AJAX Integration:
The JS ensures plus buttons are disabled when cart quantity reaches stock and works on all pages including mini-cart, cart page, checkout, and product pages.
Benefits for Your WooCommerce Store
- Avoid overselling and stock errors.
- Enhance customer experience with clear quantity limits.
- Reduce cart errors and abandoned checkouts.
- Fully compatible with Woodmart AJAX mini-cart updates.
Conclusion
With this custom min/max quantity solution, your WooCommerce store running on Woodmart theme becomes more professional, stock-safe, and user-friendly. No more over-purchases, step errors, or frustrating cart behavior.
