Products are not adding to cart

If products are not adding to cart it is typically one of the following:

Invalid Calculator Product Weight Calculation #

A product cannot be added to cart if does not have a weight. The application will fall back to 0 when it can but there are cases where you mess up the calculation so badly it cannot fall back.

Check Calculator > Calculator Settings > General > Advanced Config > Product Weight Calculation

When in doubt set Product Weight Calculation to a fixed value and remove your formula.
Example: 10

SKU and Inventory Location Problem #

By default new calculators are set to use a SKU that is “Same as default variant SKU“. This means when the app creates new variants the variant will have the same SKU as your default variant.


This can be a problem if your product default variant does not have a SKU set in Shopify and you have multiple Locations set up in Shopify.

– Edit the product in Shopify, edit a variant, select the first variant in the list of variants (often named Default Title) and set a SKU.

Another solution is to change the SKU method to one where the app will set its own SKU rather than relying on a SKU existing.

– Same as selected variant SKU (might not always work)
– Created by app (random)
– Calculated from a Formula

Inventory Location not appropriate for product #

This typically happens if you have the Calculator Inventory Location set to something that returns an invalid value.

Example: You have First Active Location selected in App and Shopify returns location not available for the product or that does not have stock.

Same thing can happen for any of the inventory locations. Always make sure it will be valid for the product associated with the calculator.

Add to Cart Script that is invalid #

You have set an Add to Cart Script that is invalid for your theme or has errors.

Go to Settings > Add to Cart Script

Check for errors or remove scripts. You should not have these set unless you know what you are doing or using an Ajax Cart which should also mean you know what you are doing. For everyone else, hire a developer or leave this setting alone.

UNCHECK your Calculator > Calculator Settings > General > Advanced Config > Run a script after product added to cart


jQuery Problem #

If products are not adding to cart or the spinner appears then stays on screen, you likely have a JQuery conflict or JQuery is missing.

See Dealing with JQuery Conflicts