Should I contribute to a Roth or Traditional 401(k)?

It depends on whether your tax rate is higher now or will be higher in retirement. If you expect a lower tax rate in retirement (for example, you're at peak earnings), Traditional contributions save more. If your tax rate is lower now than it will be later (early career, expecting income growth), Roth contributions come out ahead. Use a Roth vs Traditional calculator to compare the after-tax outcome for your specific tax rates.

What should I do with my old 401(k) when I change jobs?

You generally have three options: leave it in your old employer's plan, roll it into your new employer's plan, or roll it into an Individual Retirement Account (IRA). A rollover to an IRA usually gives you more investment choices and lower fees, but if your old plan has strong low-cost funds, leaving it can be fine. Use a 401(k) rollover calculator to compare the long-term fee impact of each option.

What is the backdoor Roth strategy?

The backdoor Roth is a two-step process for high earners whose income exceeds the Roth Individual Retirement Account (IRA) contribution limits. You contribute to a Traditional IRA (which has no income limit for non-deductible contributions), then convert that balance to a Roth IRA. The conversion is legal and widely used, but watch out for the pro-rata rule if you already have pre-tax money in any Traditional IRA — the IRS treats all your Traditional IRA balances as one pool when calculating taxes on the conversion.

Roth vs Traditional — Which Calculator Do You Need?

The Retirement Calculators at a Glance

VaporCalc has six tools that cover retirement planning from different angles. Here's what each one answers:

Comparison of VaporCalc retirement calculators and what each one is best for
Calculator	Best For
Roth vs Traditional	"Should I contribute to Roth or Traditional?"
401(k) Calculator	"How much will my 401(k) be worth at retirement?"
Employer Match Optimizer	"Am I contributing enough to get the full match?"
401(k) Rollover Calculator	"Should I roll my old 401(k) to an Individual Retirement Account (IRA)?"
Required Minimum Distribution (RMD) Calculator	"How much must I withdraw from my Traditional IRA/401(k) each year?"
Backdoor Roth Guide	"I earn too much for a Roth IRA — what are my options?" (article, not calculator)

Which Calculator Should I Use?

Start with the question that matches your situation:

1. "Roth or Traditional — which should I pick?"

Key decision factor: Compare your current marginal tax rate to what you expect in retirement. If your rate is higher now, Traditional saves more. If it's lower now, Roth wins. Not sure? Splitting contributions 50/50 gives you tax diversification — flexibility to draw from whichever account is more tax-efficient each year in retirement.

Start with the Roth vs Traditional Calculator. Enter your current and expected retirement tax rates, and it shows the after-tax difference over time.

Want the full explanation? Read Learn: Roth vs Traditional.

2. "How much should I contribute to my 401(k)?"

Two steps:

Get the full match first. Use the Employer Match Optimizer to find the minimum contribution that captures every dollar your employer will match. This is the highest guaranteed return you can get — don't leave it on the table.
Then project your balance. Use the 401(k) Calculator to see how your contributions, match, and investment growth add up over the years to retirement.

If you're deciding whether to prioritize your 401(k) versus other accounts (Roth IRA, Health Savings Account, taxable brokerage), see Learn: Tax Optimization for the recommended contribution order.

3. "I'm changing jobs — what do I do with my old 401(k)?"

Use the 401(k) Rollover Calculator to compare leaving your balance in the old plan versus rolling it to an IRA.

Rule of thumb: If your old plan charges high fees (above 0.5% per year), rolling to a low-cost IRA usually wins over time. If your old plan has institutional-class funds with very low fees, leaving it can be perfectly fine.

For a complete checklist — including health insurance gaps, equity vesting, and total compensation comparison — see the Changing Jobs guide.

4. "I earn too much for a Roth IRA"

If your income exceeds the Roth IRA contribution limits, the Backdoor Roth guide walks through the two-step workaround: contribute to a non-deductible Traditional IRA, then convert to Roth.

Watch for the pro-rata rule. If you have existing pre-tax money in any Traditional IRA, the IRS taxes your conversion proportionally based on your total Traditional IRA balance — not just the amount you're converting. This can make the backdoor Roth partially taxable.

5. "I'm retired and have to take distributions"

Once you reach age 73 (as of 2023 rules), the IRS requires you to withdraw a minimum amount each year from Traditional IRAs and 401(k)s. Use the RMD Calculator to see your required minimum distribution (RMD) schedule year by year.

Planning ahead? Consider doing Roth conversions before RMDs start. Converting some Traditional money to Roth during lower-income years can reduce future RMDs and the taxes on them. The Roth vs Traditional Calculator can help you model the conversion trade-off.

When to Use Multiple Calculators Together

Most retirement decisions involve more than one calculator. Here are the common combinations:

Starting a new job

Employer Match Optimizer — find the contribution rate that gets the full match
401(k) Calculator — project how that contribution grows to retirement
Roth vs Traditional — decide whether to make those contributions Roth or pre-tax

Approaching retirement

RMD Calculator — preview your required distribution schedule
Roth vs Traditional — evaluate whether pre-retirement Roth conversions make sense
Withdrawal Rate Simulator — test whether your savings can sustain your spending

High earner, mid-career

Roth vs Traditional — check if you benefit more from pre-tax or after-tax contributions
Backdoor Roth Guide — if income exceeds Roth IRA limits
HSA Calculator — maximize the triple-tax-advantaged Health Savings Account

Still Not Sure? Start Here

These learning articles explain the underlying concepts in depth:

Employer Benefits & 401(k) — how 401(k) plans work, vesting, contribution limits
Roth vs Traditional — full comparison of tax treatment, income limits, and withdrawal rules
Tax Optimization — the best order to fund different account types