<prompt> Human: Hey guys,I have been lurking here and posting on a few different user names over the years, but this is my first real contributing post. I just wanted to add something back to the community.This is a PSA about how 401k contributions can actually make you a lot more money than youd think by reducing your taxable income.Lets say for example I am an Illinois resident and my salary is 100k just to pick a round number. My monthly take home pay each month after taxes, social security, and medicare assuming no special considerations like tax-exempt status is 5688.52.Now lets say that I decide to contribute 10,000 this year to the company 401k plan. When my employer calculates my paycheck for withholding purposes, my taxable income is now 90k. My take home each month is now 5173.02.Wait a minute, you might say, thats only a few hundred dollars less than before. Right! The difference is only 515.50. That works out to 6,186 a year. But we were withholding a whole 10k in the 401k. The 401k tax deduction basically conjured up 3,814 out of thin air.If I were to max out my 401k contributions now to 18k, the difference is even greater. I would have a taxable income of 82k and end up with a an extra 6726.00 at the end of the year.If you want to follow along with me here, I am using the Paycheck City salary calculator here and doing the following calculation.- First, get your take home pay assuming no 401k contribution by plugging your gross income into the salary calculator.- Take your 401k contribution, subtract it from your salary. Plug that number into the salary calculator.- Subtract the second number from the first number, multiply by 12.- Subtract the result from your 401k contribution.Note that none of this presupposes you have an employer match. I knew that 401ks were a good deal before doing this little exercise, but I thought a lot of that had to do with it being an employer matching program. Im frankly surprised at what a good deal 401ks are even without it. I started this research when considering if I should max out my 401k even though I dont get an employer match. Even without the match, its a great deal.To summarize, 401ks are basically a way of getting free money, even if you get no employer match, by reducing your taxable income.Also note: if you dont have a 401k plan, you can make tax-deductible IRA contributions up to 5500. So even if you are just working a part-time job or waiting tables, you can still use the magic explained above to make extra money appear.Edit: formattingEdit2: formatting again, everything was broken after cping from the original post that the bot took downCaveats:- As someone noted, I should have accounted for the payroll tax on the withheld 401k money, which you still have to pay. So the numbers above are slightly off. However the overall situation is the same, you get a big bump in savings by taking advantage of the tax deduction.  <response>: Nice write up, 1. Another 1 for paycheckcity.com. Best calculator Ive ever seen for calculating net pay - just make sure you check the appropriate boxes for deductions in terms of what is taxable or not. 