A deduction is not a tax rate.
OK, for fun.
Here's the basic way to calculate taxes using the standard deduction.
Let's say you make $50,000. The standard deduction is $5,000. That makes your taxable income $50,000 - $5,000 = $45,000.
Let's make up some tax brackets:
$0-$10,000: 1%
$10,001-$25,000: 2%
$25,001-$50,000: 3%
To figure out the tax owed, you compare your taxable income to the brackets.
45,000 > 10,000, so the first 10,000 is taxed at 1% = $100
45,000 > 25,000, so the amount BETWEEN 10,000 and 25,000 is taxed at 2%, so $15,000 x 0.02 = $300
45,000 < 50,000, so the amount above 25,000 is taxed at 3%: 45,000 - 25,000 = 20,000. $20,000 x 0.03 = $600
So, the total amount paid in taxes = $100 + $300 + $600 = $1,000
That's how it's done in California (although with different, less pretty, numbers).
Indiana is simpler. No standard deduction, and a flat rate of 3.23%.
Now that you know how to do it, you can apply the process to the actual numbers and find the following:
For a gross income of $45,000:
Indiana: $1,453.50
California (filing individually): $1,436.55
California (filing jointly): $608.37
For a gross income of $90,000:
Indiana: $2,907.00
California (filing individually): $5,735.45
California (filing jointly): $2,873.17
Feel free to check my math.