Mega Backdoor Roth Calculator
Age 50+ allows catch-up contributions ($7,500 extra)
2024 limit: $23,000 ($30,500 if age 50+)
Check your plan documents or ask HR. Not all plans offer this.
This is critical - you must be able to convert while still employed
What is a Mega Backdoor Roth?
The Mega Backdoor Roth is a strategy that allows you to contribute up to $69,000 ($76,500 if 50+) to a Roth account in 2024, far exceeding the standard $7,000 Roth IRA limit.
- Max out your traditional 401(k): $23,000 ($30,500 if 50+)
- Get employer match (varies by company)
- Make after-tax (non-Roth) contributions to fill remaining capacity
- Immediately convert after-tax contributions to Roth 401(k) or Roth IRA
- Your 401(k) plan must allow after-tax contributions (not all do)
- Plan must allow in-service conversions or in-plan Roth conversions
- You must have income high enough to max out contributions
- Get tens of thousands into Roth accounts annually
- No income limits (unlike regular Roth IRA contributions)
- Tax-free growth and withdrawals in retirement
- Can combine with regular backdoor Roth IRA ($7,000 more)
- Convert frequently to minimize taxable gains on earnings
- Some plans auto-convert after-tax contributions
- Track your after-tax basis for tax reporting
- This is legal and IRS-approved (not a loophole)
Note: Only about 20-30% of 401(k) plans offer this option. Check with your HR or plan administrator.
Use this mega backdoor roth calculator to compute personal finance results from your inputs.
Formula
Available for after-tax = Total limit - Employee deferral - Employer match Mega backdoor opportunity = min(After-tax contribution, Available space) If in-plan conversion: Can convert to Roth immediately (no tax on growth) If not: Can roll to Roth IRA when leaving job (pay tax on gains)