Should I refinance?

[JohnDoe]

Current loan is 30yr(25 left) at 6.5%. I've been paying extra so that it will be done in 2019.

I think I could refinance at 5.5% for 15 years. Make the same pmt I'm paying today and have it finished in 2018 with 10k less interest paid.

Is that enough to pull the trigger on a refinance? I'm not sure what my closing costs would be on a 0 points loan at 5.5%, but I'm looking into it.

JD