What does 45k a yr equal to after taxes are taken?

there is not near enough information to answer this question with any accuracy, but generally, without any other exemptions and without state taxes your net would be about $41,400

Don’t forget FICA and Medicare taxes, which will drop that net some more. Specifically, by 5.6% until the current “rebate” (or whatever they’re calling it) is given up, and the total rate goes back to 7.65% (plus the employer’s matching 7.65%). And since that comes off the top (before income taxes are deducted), you’ll have to subtract $2520 from that $41,400, so your net will be around $38,880, again assuming no state or municipal income tax.

State and city taxs ny to be exact

Here is a website that you can play with to see pretty accurately what it all amounts to.

My husband’s gross pay last year was over $70K, but his net ended up being about $48K. We did the math and he has about 33% of his check taken out for taxes (state and federal), Medicare, FICA, and insurance each week. And he lists 1 for allowances. Sucks – 20+ overtime hours weekly means Uncle Sam kills him in taxes. I’ve heard that, in general, if you take 25% off of your gross pay, that’s a safe bet for taxes, medicare, FICA, and maybe insurance. That would put your net pay just under $34K. But since someone else guessed a good bit higher than that, I could’ve been told wrong. Plus, with 3 dependents, you’d naturally bring home more than my husband would at the same salary. $38–41K is probably what you’re looking at.

Tax Calculations for the Tax Year 2016/17
Gross Income: $45k
Filing Status: Single
No. Dependents: 3

Results
Federal Tax: $2,911.25
Social Security: $2,790.00
Medicare: $652.50
Total FICA: $3,442.50

You Take Home: $38,646.25

link