@athan892 In a typical month of 2017, my paycheck at UW CSE was like this:
Graduate Student 50% Appointment: $ 2,749.00
Federal Income Tax withheld: $ 344.76
UAW Local 4121 union due $ 32.72
Workers' compensation insurance $ 8.78
Net income $ 2,362.74
Hope it helps!
A few things to keep in mind:
Your base pay will differ depending on your academic department. See this page for a complete list.
Your pay is subject to federal income tax (~12.5% effective rate for 30k) but exempt from Medicare and Social Security taxes.
The state of Washington is one of 9 states that do not levy any income tax. In its stead, you will be subject to a fairly high sales tax (10.2%) and annual vehicle registration tax ($120 + 1.1% of valuation).
UW is one of the few institutions where graduate students are unionized. Thus, you will be required to pay a union membership due (1.44% of pay). See UAW Local 4121.
UW will pay 100% of health insurance premium on your behalf. The insurance also includes dental and vision benefits. You may also enroll dependents for a fee.
You will be still be responsible for miscellaneous fees, including fees for athletic facilities and monthly bus pass (U-pass). This should run about 300 dollars each quarter.