I know this is a hot button topic and I do not want to start a debate in that regard because there are multiple forum posts and blog comments that hash this debate out. What I am asking for help with is figuring out the math to determine how much one would need to invest in a taxable account to make it "mathematically correct". I do not want to fall into the trap (if my wife and I choose to invest) of not actually investing the money necessary for it to be the smart move.

Situation

Payoff Amount: $44,511.10 (Current Prinicple: $44,433.79)

Interest rate: 2.74% variable via Laurel Road (term 5 years ending 12/2022)

Monthly Payment at current rate: $810.58

AGI after maximizing tax advantaged retirement accounts for FY2018 (start first attending job 8/2018): $185,966.63

We could payoff the balance by the end of my fellowship in 6/2018. Before taking an interest in financial education, I was always frugal and a saver. My wife is the same way but to a slightly lesser degree. Our goal was to max out her 403b which had a match (mine did not in residency) but other than that throw extra money at my student loans. The lack of financial knowledge cost 3-4 years of Roth IRA contributions!

Now that we have a low interest rate, it makes sense to me that investing would yield a greater return (in theory). However, after reviewing many of the threads that mathematically derive the benefit of investing (compounding) vs. debt repayment I get lost and realize that I am not actually able to do the math myself to calculate how much to put into the taxable account to get an expected positive ROI when compared to paying off my student loans.

Thanks.

Situation

Payoff Amount: $44,511.10 (Current Prinicple: $44,433.79)

Interest rate: 2.74% variable via Laurel Road (term 5 years ending 12/2022)

Monthly Payment at current rate: $810.58

AGI after maximizing tax advantaged retirement accounts for FY2018 (start first attending job 8/2018): $185,966.63

We could payoff the balance by the end of my fellowship in 6/2018. Before taking an interest in financial education, I was always frugal and a saver. My wife is the same way but to a slightly lesser degree. Our goal was to max out her 403b which had a match (mine did not in residency) but other than that throw extra money at my student loans. The lack of financial knowledge cost 3-4 years of Roth IRA contributions!

Now that we have a low interest rate, it makes sense to me that investing would yield a greater return (in theory). However, after reviewing many of the threads that mathematically derive the benefit of investing (compounding) vs. debt repayment I get lost and realize that I am not actually able to do the math myself to calculate how much to put into the taxable account to get an expected positive ROI when compared to paying off my student loans.

Thanks.

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