Use this investment calculator to find out how much difference $50 per month will make over 20 years, or $100 will make over 10 years. Overall, if you're young, have a secure job, and have no big money needs coming up, then it makes sense to put as much into your 401(k) account as your employer will allow you.The 401(k) plan is so easy that you may even forget you're putting money into it.verall, if you're young, have a secure job, and have no big money needs coming up, then it makes sense to put as much into your 401(k) account as your employer will allow you. The 401(k) plan is so easy that you may even forget you're putting money into it.