Rollover IRA Growth Calculator: What a Rolled-Over Balance Builds

Work out what a rollover IRA grows to from the balance you rolled over plus any ongoing monthly contributions — so you can see the long-term value of consolidating an old 401(k) and continuing to invest it.

✓ Editorially reviewed Updated May 22, 2026 By Ugo Candido
Investment Details
$
The balance rolled over from a former employer's 401(k) or another retirement account into the IRA.
Default sourced from S&P Dow Jones Indices (as of December 31, 2025).
$
Any new monthly contributions you add (subject to annual IRA limits, which this calculator doesn't enforce).
Your estimate $—

Adjust the inputs and select Calculate for a full breakdown.

Compare Common Scenarios

How the numbers shift across typical situations for this calculator:

ScenarioFuture valueTotal contributionsTotal interest earned
$50k + $500/mo · 6% · 15yr$268,114.03$140,000.00$128,114.03
$25k + $0/mo · 7% · 25yr (no new adds)$143,135.46$25,000.00$118,135.46
$100k + $500/mo · 6% · 20yr$562,040.90$220,000.00$342,040.90
$15k + $300/mo · 7% · 30yr$487,738.76$123,000.00$364,738.76

How This Calculator Works

Enter the balance rolled over from a former employer's plan, any new monthly contributions, the return you expect, and the number of years. The calculator compounds the balance monthly and shows the ending value and the growth beyond your contributions.

The Formula

Future Value with Regular Contributions

FV = P(1 + r)^n + PMT · ((1 + r)^n − 1) / r

P = starting amount, PMT = monthly contribution, r = monthly rate (annual ÷ 12), n = number of months

Worked Example

A $50,000 rollover plus $500 a month for 15 years at 6% grows to about $268,114 — of which roughly $128,114 is investment growth. Rolling an old 401(k) into an IRA keeps the money tax-deferred (no tax or penalty on a direct rollover) while typically opening up far more investment choices and often lower fees than an old employer plan. Consolidating scattered old accounts into one IRA also makes them easier to manage and rebalance.

Key Insight

A rollover IRA is one of the most common and worthwhile retirement housekeeping moves, and the growth math shows why keeping the money invested matters. The key mechanics: a direct rollover (funds moving trustee-to-trustee) avoids any tax or the 10% early-withdrawal penalty and preserves tax-deferred growth — never take a check to yourself and risk the 60-day rule and mandatory withholding. The advantages over leaving money in an old 401(k) are usually broader investment options and potentially lower fees, plus the simplicity of consolidating multiple old accounts. A few caveats this calculator doesn't model: rolling a traditional 401(k) into a traditional IRA stays tax-deferred, but converting to a Roth IRA triggers tax now (sometimes worth it); IRA contribution limits cap new annual contributions; and a rollover IRA can complicate the 'backdoor Roth' strategy due to pro-rata rules. The biggest driver of the outcome remains time and consistent contributions — consolidating and continuing to invest, rather than cashing out an old balance, is what lets compounding do its work.

Frequently Asked Questions

How is rollover IRA growth calculated?

The rolled-over balance and each monthly contribution compound at the expected return (annual rate ÷ 12 per month). $50,000 plus $500/month for 15 years at 6% grows to about $268,114, with roughly $128,114 of that being investment growth.

Is a 401(k) rollover taxable?

A direct rollover (trustee-to-trustee) into a traditional IRA isn't taxed and avoids the early-withdrawal penalty — the money stays tax-deferred. Converting to a Roth IRA triggers income tax on the amount now. Avoid taking a check yourself, which can trigger withholding and the 60-day redeposit rule.

Why roll an old 401(k) into an IRA?

Usually for more investment choices and potentially lower fees than an old employer plan, plus the simplicity of consolidating scattered accounts into one. It keeps the money tax-deferred and growing. (Some prefer to keep a 401(k) for its stronger creditor protection or to allow a backdoor Roth — weigh your situation.)

Can I keep contributing to a rollover IRA?

Yes, subject to the annual IRA contribution limit (and income rules for deductibility or Roth eligibility). This calculator lets you add monthly contributions but doesn't enforce the IRS limit, so make sure your annual additions stay within the allowed amount.

Does a rollover IRA affect a backdoor Roth?

It can. Having a pre-tax balance in a traditional/rollover IRA triggers the pro-rata rule, which can make a backdoor Roth contribution partly taxable. If you plan to use the backdoor Roth strategy, consider whether to roll into an IRA or keep funds in a 401(k) — consult a tax professional.

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Data Sources & Benchmarks

This calculator draws on 1 independent, dated source. The starting values for expected annual return are taken from the benchmarks below and refresh whenever the snapshots are updated.

10.30% Provisional
S&P 500 long-run annual return
S&P 500 Index — Long-Run Annualized Total Return
S&P Dow Jones Indices · as of December 31, 2025
View source ↗

Methodology & Review

Ugo Candido ✓ Editor
Wrote this calculator and is responsible for its methodology and review.

The future value compounds a starting balance and a fixed monthly contribution at the annual return, compounded monthly. It assumes deposits at month end and a constant return; it ignores fees, taxes, IRS contribution limits, and the year-to-year volatility of real returns.

Written by Ugo Candido · Last updated May 22, 2026.