Why use this API?

Because calculating income tax manually, especially in a spreadsheet, is harder than it should be. This API makes it easier.

If you really want to do it manually, I’ve previously used this complicated VLOOKUP method.

What is MAGI?

Modified adjusted gross income. When you use this API, you should input your MAGI, not your gross income. This lets you work out all of your deductions in your spreadsheet, which can be as simple or as complicated as you want.

What brackets / math does this API use?

The brackets come from Nerd Wallet. The API code will be updated to account for any bracket changes in the future. You can check which years are supported by issuing a request for an invalid year, using a URL like: https://api.taxapi.net/income/single/50000/invalidyear.

Note that specifying a year is optional. If you don’t specify a year, the API will default to using the most recent year it has available.

How can I use this API with multiple cells in a spreadsheet?

This probably depends on the functions that your spreadsheet software offers. In Google Sheets, I’ve used CONCAT to take a value from one cell to build the API URL in another cell. For example, if my MAGI was in A1, and my API call was in A2, it would look like this:

1 50000
2 =IMPORTDATA(CONCAT("https://api.taxapi.net/income/single/", A1))

I need help using this API

If you’re having trouble using this API, please try loading it in a browser, eg. navigate to https://api.taxapi.net/income/single/50000, substituing whatever filing status and MAGI number you want. If it loads in a browser, then the API itself works. Any trouble that you’re having in a spreadsheet would be outside the scope of support for this API.

If you are having trouble getting the API to work, even when called directly in a browser, please use the email link below to email the author of this API. Please include the specific URL that you’re using when you hit the API, and include any error message you might receive.

Any support requests outside the scope of calling this API directly in a browser (or curl) will not be supported.