Mega Backdoor Roth Calculator

This calculator helps determine how much you can contribute to a Roth 401(k) after accounting for your regular 401(k) contributions and employer match. Your total tax-benefit contributions are subject to an annual IRS limit that must be followed.









Potential Mega Backdoor Roth Contribution (after-tax 401(k)) ($):

Annual Total 401(k) Contribution Including Employer Match ($):

Mega Backdoor Roth Calculator Instructions

The Mega Backdoor Roth 401(k) is a strategy that allows individuals to contribute significantly more to tax-advantaged retirement accounts than the standard limits. Here’s how it works and the key details you need to know:

Annual Total Contribution Limits of All Tax-Deferred and Tax-free Contributions

  • For 2024, the total contribution limit to a 401(k) plan is $69,000 (or $76,500 for those over age 50). This total includes:
    • All employee pre-tax 401(k) and Roth 401(k) contributions to regular or traditional 401(k) plans (up to $23,000 or $30,500 if over 50).
    • All employer contributions or matches.
    • All after-tax contributions to 401(k)s.

Note, the above includes all of your contributions, regardless of how many separate accounts you have.

Process for Mega Backdoor Roth

  1. Max out your pre-tax 401(k) and after-tax Roth 401(k) contributions: First, contribute the maximum allowed ($23,000 or $30,500 if over 50) to your 401(k) using pre-tax contributions.
  2. Make after-tax 401(k) contributions: Once you’ve maxed out your regular 401(k) contributions, you can make after-tax 401(k) contributions up to the overall $69,000 (or $76,500 if over 50) limit, including any employer contributions. Note: after the after-tax contribution to the regular 401(k), you can roll them over into a Roth 401(k), assuming a so-called in-service or in-plan distribution.

See Mega Backdoor Roth Savings Explained for more details.

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