Traditional vs Roth 401(k) Calculator

How to do it

1. 1
   Step 1: Open Traditional vs Roth 401(k) Calculator and add your input

   Type your numbers or text, add your file, or pick the options you need. Nothing is uploaded: everything stays in your browser.

2. 2
   Step 2: What Traditional vs Roth 401(k) Calculator does

   Compare a traditional and a Roth 401(k) by your tax rate today and in retirement.

3. 3
   Step 3: Read the result and compare

   The result appears at once. Change one value to see how the answer moves, then keep the figure that fits your case.

4. 4
   Step 4: Copy or save it

   Copy the result or download it. For an important decision, confirm it with the official source or an adviser.

About this tool

Enter a yearly contribution, how many years you will invest, the return and your tax rates now and in retirement. Both options cost you the same take-home pay today, so the winner depends on whether your tax rate later is higher or lower than now.

The comparison

A traditional contribution of $10,000 costs you $10,000 × (1 − tax rate now) in take-home pay. To spend the same amount, a Roth contribution is $10,000 × (1 − tax rate now). Both grow at the same return. At the end the traditional balance is taxed at your retirement rate; the Roth balance is not.

Rule of thumb

If your tax rate in retirement is lower than today, traditional wins; if it is higher, Roth wins; if equal, they tie. The gap grows with the years.

Other points

Roth money can come out tax free and has no required withdrawals during your life. Traditional gives you the deduction now. State tax rates can differ now and later, so there are separate boxes. The tool uses monthly contributions with monthly compounding and a constant return.

Worked example

$10,000 a year for 30 years at 7%, 24% tax now and 22% in retirement: the traditional balance of about $1,016,600 is worth $793,000 after 22% tax, the Roth balance (from $7,600 a year) is $772,600, so traditional wins by about $20,300.

Tips for best results

Check every box before you rely on a result, because one wrong digit changes the whole answer. Use the exact figures from your payslip, bill, certificate or contract, and keep a note of the date you calculated. Rates, thresholds and rules change from time to time, so for tax, fees and legal matters treat the output as an estimate and confirm with the official source named on this page. You can run as many scenarios as you like; nothing is saved or sent, and refreshing the page clears the boxes.