IRS has a free hotline where you can ask questions like this. We used to claim ourselves and each child and our refund would be around 2 grand. we used that for vacations. We maxedout the 401k every year and IRA's also.( my spouse does not work so we qualified for max on that as well )
If possible max your 401k or slowly increase % each year since you get a raise each year. You will barely notice a difference. We also added $100 a month toour mortgage payment going towards the principle. I believe we also increased this once the kids had moved out.
Doing that cut our 30 year mortgage to paid off in 17 years saving over $130,000 in mortgage interest. I was able to retire several years earlier ( 58.5) instead of waiting for social security to kick in. well worth it for us.
Everybody's situation is different so keep asking questions to tax people and financial people. We really liked most of Dave Ramsey says on his radio program and books. Mainly cut out all debt and save save save.
good luck.