Edit - I might explain it here better: http://www.cougarboard.com/board/message.html?id=19082654

If you are married filing jointly, add up the 2017 and 2018 amounts and do a comparison. Add, Taxes you pay, plus mortgage interest plus tithing and fast offering and missionary (if you have one) by year totals as you currently expect to pay.

Current Situation:

1. Compare your 2017 amounts to $12,700, this year's standard deduction - i.e., subtract $12.7 to see what is "extra".

2 Compare your 2018 amounts to $24,000, next year's standard deduction - i.e., subtract $24 to see what is "extra".


Then determine what happens if you change - in your example, accelerate $5K this year:

3. Add $5K to 2017 and subtract $5K from 2018 from the above and compare which provides you the largest deduction above and beyond the standard deduction - i.e., the total two year "extra". If you have more "extra" accelerating the $5K, then you should do it, and try to scrape up a little more if you can...Bottom line is that next year, it has to be below $24 due to tithing acceleration - otherwise no significant benefit if income is generally the same.