Price custom products by size, area, characters, files and quantity, with setup fees, limits and conditional options.
Available Updated Oct 22, 2026Version 1.0.0CS-Cart, Multi-Vendor 4.17.2 – 4.21.x No core file edits
Built for
Advanced Product Options & Price Formulas: overview1 of 16
What it does
For print shops, signs, glass and frames, curtains, engraving, furniture and any made-to-measure product. Core options only add a fixed amount or a percent; this add-on calculates the price from what the customer enters: area, length, text length, uploaded files or quantity. Add one-time setup fees, number limits with units, text limits and options that appear only when another option is chosen. It works with global options, vendors and products priced in another currency.
How it works
In the option editor, give an option a code, limits and a price rule: a formula such as width x height x rate, or a price per character, line or file, per item or once. Add conditions to show it only when needed. On the product tab, add a product formula, a minimum price or a setup fee and try it in the test calculator. Shoppers see the options adapt and the breakdown update; the cart and orders keep each amount.
Features
Price formulas with option codes, variant values, quantity and the base price
Price per character, word, line or uploaded file, with free units
One-time setup and artwork fees charged once per cart line and taxed like the product
Number inputs with minimum, maximum, step, default value and unit
Text limits with a live character counter
Conditional options that show and hide based on other selections
Live price breakdown on the product page, in the cart, orders, invoices and e-mails
Server-side validation for the storefront, admin orders and the REST API
Formula check and test calculator in the admin panel, with a safe formula parser
Global options, Multi-Vendor vendor editing, product currencies and the REST API supported
Interplay: products that need input are opened from the product page, not the B2B quick order form, and Product Cost & Profit reports count one-time fees as an order surcharge
What you get
Package
kv_product_options_pricing-1.0.0.zip, installed through Add-ons → Manage add-ons
Updates & support
12 months included. Download new versions from your account and install them in Add-ons → Manage add-ons or the Upgrade Center.
License
1 production installation. Staging, dev and localhost are free and unlimited. The add-on keeps working after the update period ends. How licensing works
Compatibility
We list only the builds we install and test on. “Tested” means the full test plan was run on that build; “Supported” means the build is inside the supported range and uses the same hooks.
CS-Cart version and edition compatibility
CS-Cart version
CS-Cart
CS-Cart Ultimate
Multi-Vendor
Multi-Vendor Ultimate
4.22 and later
Testing next
Testing next
Testing next
Testing next
4.21.2
Supported
Supported
Tested
Supported
4.20.x
Supported
Supported
Supported
Supported
4.19.x
Supported
Supported
Supported
Supported
4.18.x
Supported
Supported
Supported
Supported
4.17.2
Tested
Supported
Tested
Supported
Before 4.17.2
Not supported
Not supported
Not supported
Not supported
Last tested build: Multi-Vendor 4.21.2, Oct 22, 2026Tested on: Multi-Vendor 4.17.2, CS-Cart 4.17.2, Multi-Vendor 4.21.2
Requirements
Platform
CS-Cart or Multi-Vendor 4.17.2 – 4.21.x
PHP
PHP 7.2.5 – 8.3, as supported by your CS-Cart version
Platform
Tested on CS-Cart Ultimate 4.17.2, Multi-Vendor 4.17.2 and Multi-Vendor 4.21.2
Requirement
Products with options (Products → Products → product → Options) or global options (Products → Options)
Core changes
None. Hooks and template overrides only
1.0.0
Oct 22, 2026
Latest
Added 13
Advanced pricing and rules for product and global options: formula code, number input with minimum, maximum, step, default and unit, text limits (characters, lines), "Required when shown", price rule (formula, per character, word, line or uploaded file with free units) charged per item or once per cart line, and conditions (all or any) that show the option only when other options have certain values.
Formula values for select, radio and checkbox variants.
Product price formula (added to the price or replacing the base price), minimum price per item and one-time setup fee on the new Price formula tab, with a formula check and a test calculator (breakdown, hidden options, validation messages, variable values; unsaved formulas included).
Safe formula language with its own parser: arithmetic, comparisons, logic, conditional expressions and the functions min, max, round, ceil, floor, abs, sqrt, pow, clamp, if, round_to, ceil_to, floor_to; strict limits, no code execution.
Storefront: conditional options hidden, number inputs with unit and limits, character counter, inline messages, live price update while customers type or change the quantity, and a price breakdown under the options.
Server-side validation on add to cart and cart updates (storefront, admin order management, REST API); hidden option values and files are removed.
One-time fees as an order surcharge ("One-time fees") taxed with the product's tax classes, in cart, checkout, orders, invoices and e-mails; Multi-Vendor sub-orders carry their own fees.
Breakdown stored with each order item and shown in order details, invoices and e-mails; placed orders keep their amounts when rules change.
Products > Option price rules overview page.
Multi-Vendor: vendors can edit the rules of their own products when allowed.
Product Price in Any Currency integration: formulas in the product's currency.
REST API: option rules (kv_pop, kv_pop_value) and product formulas (kv_pop).
Licence client: without a valid license, new carts use the core option prices; placed orders keep their prices, fees and breakdowns.
Tested on Multi-Vendor 4.17.2, CS-Cart 4.17.2, Multi-Vendor 4.21.2. First release.
Can I price by area, like width Ă— height?
Yes. Give the width and height options the codes width and height, make them number inputs and write width height / 10000 25 (price per square metre with sizes in cm) as the product formula or as the formula of the height option. Use a material option with formula values per variant to make the rate depend on the material.
Do the core option modifiers still work?
Yes. Fixed and percentage modifiers of variants are applied first, and the add-on adds its amounts on top. The formula variable price contains the price with the core modifiers.
Is a one-time fee multiplied by the quantity?
No. Fees set to Once per cart line and the setup fee are charged once per cart line and shown as One-time fees in the totals. They are taxed with the product's tax classes (or not at all, see the settings).
Can options appear only when another option is selected?
Yes, with conditions in Advanced pricing & rules → Show this option. Use Required when shown instead of the core Required checkbox for such options.
Are the checks done on the server too?
Yes. Number limits, text limits, required options and conditions are checked again when the product is added to the cart or the cart is updated, also for REST API and admin orders. Hidden options never reach the order.
Can a formula run code or break my store?
No. Formulas are read by the add-on's own parser with a fixed list of operators and functions; there is no way to call PHP. A formula that fails at runtime (for example a division by zero) counts as 0 and the admin test calculator shows the error.
What happens to placed orders when I change a rule?
Nothing. Orders keep their prices, fees and breakdowns. When you edit a placed order, unchanged items keep their amounts.
Do catalog promotions and discounts apply to formula prices?
Yes. Catalog and cart promotions are calculated after the options, so they apply to the full price per item.
Does it work with global options?
Yes. Rules are stored per option, so a global option carries its rule to every product it is linked to. Codes must be unique within each product.
Does it work with product variations?
Each variation is a product with its own options; rules are copied when options are cloned (for example when variations are created) and when a product is cloned.
What about the full page cache of CS-Cart 4.21?
The product page shows the breakdown for the default selection, the same for every visitor, and option changes are recalculated with POST requests that the cache does not store. Nothing personal is cached.
Can vendors use it?
On Multi-Vendor you decide: with Vendors can edit price rules on, vendors edit the rules of their own products.
What happens if the license lapses?
Without a valid license (no key after the 14-day start period, an invalid or revoked key, a domain the license does not cover, or no successful check for 14 days), formula prices, one-time fees, number limits and conditional options stop for new carts and products use the core option prices. Placed orders keep their prices, fees and breakdowns. Your rules stay.
The admin panel shows a license notice.
Open Add-ons → Manage add-ons → Advanced Product Options & Price Formulas → Settings → License. The status line says what is wrong: no key, a key for another add-on, a revoked license, or a domain that the license does not cover. Fix it and click Check now. See License.
Does the add-on work on my staging copy?
Yes. Subdomains of your licensed domain (for example staging.yourstore.com) and local development hosts (localhost, private IP addresses, .local, .test) are covered by the same license.
What happens if your license server is down?
The add-on keeps working. If the check fails, it retries every hour and keeps working for 14 days after the first failed check.
Does the license check slow down my storefront or checkout?
No. The check runs only in the admin panel or from cron, never on storefront or checkout requests.
Can customers add these products from the B2B quick order form?
No. A product that needs input (a required option, or a number or text field) is refused in the quick order form with a notice; the customer opens the product page and chooses the options. Products without such options work as before.
Do cost and profit reports include the one-time fees?
The Product Cost & Profit reports show the one-time setup and artwork fees as an order surcharge, not as part of the item lines, so the Items figures exclude them. The order total and invoices include them.
B2B Request a Quote (RFQ)Let business buyers request a quote for several products, send them an offer with your prices and let them check out at the quoted prices.
$99
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