Use the slider to change how much you will contribute and then you can:
See the impact on your paycheck to determine how much you can afford.
Don't leave money on the table! Make sure you take advantage of the company match, which is dollar for dollar on your first 6% of contributions.
See how your contributions can grow over time.
Are you making a large contribution? Keep in mind that the Company Match is applied equally across each paycheck, so if you max out your personal contributions before the end of the year you will lose some of the Company Match.