How does Turbox tax caculate New York Income Factor

[dukeandjinyee]

I found something very strange in Turbox's calculation. NY state tax summary page shows that the NY income factor is 0.4191. However, I don't understand how this number was calculated. The summary page also states that the federal adjusted gross income is 300784. Based on my W-2, the NY State Amount is 40293 + 147353=187646. So, my understanding is that the NY income factor should be 187646/300784 = 0.6238. I'm not sure how Turbo tax derived the income factor of 0.4191. Can you please help me understand?

[AnthonyC]

The formula used is NY Adjusted Gross Income divided by Federal Adjusted Gross Income.

The NY number used would not be the same number as shown on your W2s as that is pre-adjustments.  The line number used is line 31 of your Form IT-203.

You can see the instructions for this line here - 

https://www.tax.ny.gov/pdf/current_forms/it/it203i.pdf (page 30)

https://www.tax.ny.gov/pdf/current_forms/it/it203_fill_in.pdf