Roth vs Traditional IRA Calculator - Tax Savings Comparison

Why a $7,000 Yearly Contribution Can End Up Very Different in Roth vs Traditional

A Roth and Traditional IRA can hold the same investments and grow at the same rate, yet leave you with different spendable dollars. The difference is when you pay tax. Traditional gives you a deduction now and taxes the withdrawal later. Roth takes after-tax money now and leaves qualified withdrawals free of tax. If your tax rate falls in retirement, deferring tax helps. If it rises, paying now helps.

Consider Texas with no state income tax versus California where combined marginal rate can be higher. Someone in a higher bracket now who expects lower income later often favors Traditional. Someone earlier in career with lower bracket now who expects higher income later often favors Roth. This tool shows that math with your own brackets, not a generic rule.

For $7,000 per year over 25 years at 7% return, annual compounding: factor = ((1.07^25 -1)/0.07) = 63.249. Future before tax = $7,000 x 63.249 = $442,743. Traditional after-tax at 15% retirement = $442,743 x 0.85 = $376,331 plus tax saved now each year. Roth tax-free = $442,743 if you contributed same $7,000 after-tax. Difference is driven by bracket change and whether you invest the tax saving from Traditional.

How To Use This Comparison Without Guessing

First - Enter contribution and years. Use your actual yearly IRA amount. Example $7,000 if under 50, $8,000 if 50 or older per current IRS limit. Years is how long until you plan to start withdrawing, not your current age alone. Example 30 to 55 = 25 years. If you contribute mid-year, the factor adjusts slightly, but annual end-of-year is standard for simple comparison.

Second - Enter current and retirement brackets. Current bracket is what you pay now on last dollar of income - example 22%. Retirement bracket is what you expect to pay on withdrawals - example 15% if lower income, or 24% if higher income. Use federal only for this comparison, or combine federal + state for more complete view and note assumption.

Third - Enter return net of fees. Use 7% for balanced estimate, lower for conservative, higher for aggressive stock allocation. This is net after expense ratio, so if fund charges 0.5%, subtract it from gross.

Fourth - Compare after-tax values and difference. Press Compare. Top badge shows winner and gap. Four boxes show Traditional after-tax, Roth tax-free, future before tax, and tax saved now. Snapshot explains contribution growth and bracket impact. Try flipping retirement bracket from 15% to 28% to see winner change.

How This Tool Figures Roth vs Traditional - Formula and Sources

Source: IRS Publication 590-A for contribution rules and deduction, IRS 590-B for qualified Roth distribution, SEC compound interest guidance for future value of annuity. Method: annual contribution at end of each year, constant return, no inflation adjustment. Traditional deduction and tax are separate cash flows.

r = Return% /100 | n = Years
pow = (1+r)^n | factor = (pow -1)/r if r>0 else n
FV = C x factor | FV_start = FV x (1+r) if contribution at start
Traditional after-tax = FV x (1 - retirement%) | Roth after-tax = FV
Tax saved now = C x current% per year | Difference = |Roth - Traditional|

Verified with $7,000, 25 years, 7%, current 22%, retirement 15%:

• r=0.07, n=25, pow=5.427, factor=63.249
• FV = 7000 x 63.249 = $442,743
• Traditional after-tax = $442,743 x (1-0.15) = $376,331
• Roth after-tax = $442,743 tax-free qualified
• Tax saved now per year = $7,000 x 0.22 = $1,540
• Winner Roth by $66,412 before counting reinvested tax savings
• If retirement bracket 28%, Traditional after-tax = $442,743 x 0.72 = $318,775, Roth wins by $123,968
• If retirement bracket 10%, Traditional after-tax = $442,743 x 0.90 = $398,469, Traditional loses by $44,274 vs Roth in this simple model, but if you invest tax saving $1,540 yearly at 7%, future of saved taxes = $1,540 x 63.249 = $97,403, then Traditional total $475,734 vs Roth $442,743 — Traditional wins by $32,991

Guards: contribution 0-1M cap, years 1-60, brackets 0-50 cap, return 0-15 cap, non-finite to 0, rounding final only. No NaN display.

What Each Result Means For Your Decision

Estimated Winner After Tax: Top BigStat shows which account leaves more spendable dollars under inputs and by how much. Example Traditional wins by $32,991 when you count reinvested tax savings and lower retirement bracket.

Traditional After-Tax: Future value times (1 - retirement bracket). Example $376,331 at 15% retirement tax. If you reinvest yearly tax saving, add its future value to compare fairly.

Roth Tax-Free: Future value tax-free if qualified - 5-year rule and age 59½. Example $442,743. No tax on withdrawal, simpler for estate and RMD planning as Roth IRA has no RMD for owner.

Future Before Tax: Same for both if contribution same - $442,743 in example. Shows growth before tax difference.

Tax Saved Now: Contribution times current bracket per year - $1,540 in example. If you invest this saving in taxable or keep in Traditional comparison, it changes winner. Many people spend it, so direct after-tax comparison without reinvestment favors Roth when retirement bracket higher.

Difference Bar: Absolute gap between Roth and Traditional after-tax. Helps decide if gap justifies complexity.

Example - Same $7,000, Three Different Bracket Stories

Story 1 - Higher now, lower later - Texas engineer age 35, 32% now, 22% later, 25 years, 7%: FV $442,743, Traditional after-tax $345,340 at 22%, Roth $442,743, gap Roth +$97,403 before reinvestment. If reinvest $2,240 tax saving yearly, future of savings $141,678, Traditional total $487,018 vs Roth $442,743 — Traditional wins by $44,275. Shows why reinvesting deduction matters.

Story 2 - Lower now, higher later - Florida early career age 28, 12% now, 24% later, 30 years, 7%: n=30, pow=7.612, factor=94.46, FV $661,220, Traditional after-tax $502,527 at 24%, Roth $661,220 — Roth wins by $158,693. Early career often favors Roth.

Story 3 - Same bracket - California age 40, 22% now, 22% later, 20 years, 7%: n=20, factor=40.995, FV $286,965, Traditional after-tax $223,833 at 22%, Roth $286,965 — Roth wins by $63,132 before reinvestment. With reinvested tax saving $1,540 x 40.995 = $63,132, totals equal — $286,965 both. When brackets equal and you reinvest saving, math equal.

Common Missteps That Skew Roth vs Traditional Choice

1. Comparing $7,000 pre-tax vs $7,000 after-tax as equal cost: Roth $7,000 costs more out-of-pocket because you paid tax first. To compare fairly, either use same gross dollars or add future of tax saving to Traditional side. Otherwise Roth looks artificially better when brackets equal.
2. Forgetting income limits for deduction and Roth eligibility: Traditional deduction phases out if covered by workplace plan and income over threshold. Roth contribution phases out over income range per IRS. Check Publication 590-A for your filing status.
3. Using gross return without fees: Expense ratio 0.6% turns 7% gross into 6.4% net. Over 25 years, $7k yearly at 7% = $442k, at 6.4% = $404k — $38k difference. Enter net return.
4. Ignoring RMD and early withdrawal rules: Traditional has RMD starting at applicable age, Roth IRA owner has no RMD. Early withdrawal before 59½ may incur 10% penalty plus tax for Traditional, earnings penalty for Roth if non-qualified. Plan horizon matters.
5. Assuming brackets stay same for decades: Rates change, state moves matter, retirement income mix changes. Run three scenarios — low, mid, high retirement bracket — to see winner range rather than single point estimate.

Practical Note - How To Apply This For Real Planning

Pull your last tax return marginal rate, your IRA contribution plan, and your expected retirement income sources. If you expect Social Security plus 401k withdrawals to push you to similar bracket, Roth adds diversification and tax-free bucket. If you are in peak earning years in California at 32% plus state and expect lower bracket in Florida retirement, Traditional deduction now may outweigh Roth. Also consider that Traditional lowers AGI now which can affect credits. Keep Roth for later years when income lower. For couples, model each spouse separately if ages and brackets differ.

Important Limitations To Remember

This tool gives estimates for educational purposes only. Not tax advice. Comparison assumes constant yearly contribution, constant brackets, constant return, annual compounding at year-end, no inflation, no income phase-outs, no pro-rata rule for non-deductible Traditional, no conversion taxes, no RMD modeling. Actual IRA outcome depends on market performance, IRS limits that change, filing status, modified AGI, workplace plan coverage, state taxes, and withdrawal timing. Verify with IRS Publication 590-A and 590-B and a qualified tax professional.

Frequently Asked Questions

How does Roth vs Traditional IRA comparison work?

Traditional IRA uses pre-tax contribution that grows tax-deferred and is taxed at withdrawal in retirement. Roth IRA uses after-tax contribution that grows tax-free if qualified. Future value of yearly contributions is calculated with compound growth, then Traditional after-tax is reduced by retirement tax rate.

When does Traditional IRA give higher after-tax value?

Traditional IRA tends to give higher after-tax value when your current tax rate is higher than your retirement tax rate. You get a deduction now at a higher rate and pay tax later at a lower rate, especially if you reinvest the tax saving.

When does Roth IRA give higher after-tax value?

Roth IRA tends to give higher after-tax value when your retirement tax rate is higher than your current rate, or when you want tax-free growth and no required distributions for qualified withdrawals. Early career and low bracket years often favor Roth.

How is future value of annual IRA contributions calculated?

Future value of yearly contributions uses r = return/100, n = years, pow = (1+r)^n, FV = contribution x ((pow-1)/r). If contribution at start of year, multiply by (1+r). Traditional after-tax = FV x (1 - retirement bracket). Roth after-tax = FV if contribution same amount.

What about IRA contribution limits?

IRS sets an annual limit for combined Traditional and Roth IRA contributions. Limit includes extra amount for age 50 and over. Check current IRS notice for your filing year to confirm your eligible limit.

Does employer match apply to IRA?

No. Employer match applies to 401k, not IRA. IRA is individual. You can have both 401k with match and IRA, subject to separate limits and rules.

Does this include state taxes or fees?

This comparison uses federal tax rates you enter and a net return you enter. Enter return after fees. State taxes, penalties for early withdrawal, and income limits for deduction are not included and should be verified with IRS publications.

Does this calculator save my data?

No. Inputs are processed locally and not sent to a server for this calculator component. Closing the tab clears values.