Form 709 Schedule B line 1c : Should we just add applicable credit for all the years?

There's an online calculator that may help....https://www.taxformcalculator.com/calculator/709.html......but this thing gets wicked complicated and you should get help from a tax pro when you're preparing this form....the IRS has a lower tolerance for any mistakes on this form than any other and it only comes back to bite years down the road.

Thank you so very much! That calculator is super helpful. I wasn't aware of that earlier. I tried the calculator and ran into following questions. Thanks a lot again!

1) As in screen shot below as an example, Line 3 of Item 19 says "Total taxable gifts. Add lines 1 and 2", but it doesn't add because 110+14= 124 and not 102.. Wondering how it is coming up with that calculation.

2) The calculator also fills 0 from line 4 onwards exception for line 8. Are we not expected to compute the tax using Table for computing gift tax?

Please see my comments below regarding your Form 709 gift tax questions :

1. It is hard to recreate your exact situation from your screenshot since I do not know what was entered on the backup schedules that support Line 1 and Line 2. However, the website used may not work correctly if you entered $22 in any gift or part of a gift that qualified for the political, educational, or medical exclusions. Otherwise, Line 3 is supposed to sum Line 1 and Line 2 correctly. 
2. As stated in 2020 Instructions Form 709, page 18, the tax table should be used to compute the gift tax for the amount on Line 3 and the amount on Line 2. However, the amounts entered in Line 2 and Line 3 are under the taxable amount.  

@johnsantaclara

Thank you.