---
displayed_sidebar: servicesSidebar
---

import ParameterTypes from "@site/src/components/ParameterTypes"

# ITaxCalculationStrategy

## Methods

### calculate

`**calculate**(items, taxLines, calculationContext): Promise<number>`

Calculates the tax amount for a given set of line items under applicable
tax conditions and calculation contexts.

#### Parameters

<ParameterTypes parameters={[
  {
    "name": "items",
    "type": "[LineItem](../classes/LineItem.mdx)[]",
    "description": "the line items to calculate the tax total for",
    "optional": false,
    "defaultValue": "",
    "expandable": false,
    "children": []
  },
  {
    "name": "taxLines",
    "type": "([LineItemTaxLine](../classes/LineItemTaxLine.mdx) \\| [ShippingMethodTaxLine](../classes/ShippingMethodTaxLine.mdx))[]",
    "description": "the tax lines that applies to the calculation",
    "optional": false,
    "defaultValue": "",
    "expandable": false,
    "children": []
  },
  {
    "name": "calculationContext",
    "type": "[TaxCalculationContext](../types/TaxCalculationContext.mdx)",
    "description": "other details relevant for the calculation",
    "optional": false,
    "defaultValue": "",
    "expandable": false,
    "children": []
  }
]} />

#### Returns

Promise&#60;number&#62;

<ParameterTypes parameters={[
  {
    "name": "Promise",
    "type": "Promise&#60;number&#62;",
    "optional": false,
    "defaultValue": "",
    "description": "the tax total",
    "expandable": false,
    "children": []
  }
]} />