---
title: "Math expressions in prices and number fields"
url: https://docs.woolytech.com/en/articles/89-math-expressions-in-prices-and-number-fields
collection: "Getting started"
updated: 2026-07-31
language: en
---

# Math expressions in prices and number fields

Math expressions present a powerful tool to derive values from product data inputs. It is useful to derive arbitrary attributes like tax-included prices, tax, shipping, etc.

Some examples where Math expression can be used:

-   A custom field representing tax that equals to 21% of product price.
    
-   A "Shipping and included" price that equals product price added with a shipping fee for a marketplace that takes only shipping and tax included prices.
    

Math expressions are available in [price and sale price attributes](/article/88-advanced-price-and-sale-price-calculation). It is also available in 'Number' typed custom fields as in following screenshot:

![](https://staticfiles.gleap.io/helpcenter/65cecc47f9fbfb7f6ae1288e/20260325041347_7003.jpg)