Re-Fi Question - Can someone help me w math?

[dietcoke]

We re-fi'd in April 2020 to 15 yr loan at 3.125% on a loan of $147,000 our payment is $1024.02.

I always pay an even $1100/month.

We could refi at 2.375% for 15 years today with aprox $1500 closing costs.  Our current balance is $141,940.

Is it worth it? I'm not sure how to calculate it factoring in the extra I pay on it every month anyway. 

TIA

[Deleted]

This is the calculator I use to determine if an offer makes sense: www.nerdwallet.com/mortgages/refinance-calculator/calculate-refinance-savings