$7,500, or $8,600 if age 50+ (catch-up $1,100). Combined across traditional and Roth IRAs.

The IRS looks at all traditional IRAs. Taxable share = pre-tax balance ÷ (pre-tax + basis including this contribution). A leftover rollover IRA can tax most of a “backdoor.”

You still file it. This tab only sketches the taxable slice.

No. Confirm with a CPA if you have several IRAs.

Runs in your browser · Last updated 4 September 2026

Free Backdoor Roth IRA Calculator (US, 2026)

Free backdoor Roth IRA calculator. 2026 limit $7,500 ($8,600 age 50+); pro-rata taxable share of a conversion. Browser tool — nothing is uploaded.

Nondeductible IRA contribution ($)Other pre-tax IRA balance ($)Existing IRA basis ($)Age

Converted

$7,500

Taxable (pro-rata)

Nontaxable

$7,500

2026 IRA limit

$7,500

Pre-tax share

0.0%

Empty other IRAs first (roll to a 401k) if you want a clean backdoor. This tab does not file Form 8606.

How to use this tool

Enter the nondeductible contribution (usually the annual limit).
Add any other traditional IRA pre-tax balance and existing basis.
Read the taxable vs nontaxable conversion.

Worked example

$7,500 contribution and no other IRA: the conversion is nontaxable. Add a $22,500 pre-tax IRA and 75% of the conversion is taxable ($5,625).

Frequently asked questions

2026 IRA limit?: $7,500, or $8,600 if age 50+ (catch-up $1,100). Combined across traditional and Roth IRAs.
What is pro-rata?: The IRS looks at all traditional IRAs. Taxable share = pre-tax balance ÷ (pre-tax + basis including this contribution). A leftover rollover IRA can tax most of a “backdoor.”
Uploaded?: No.
Form 8606?: You still file it. This tab only sketches the taxable slice.
Is this tax advice?: No. Confirm with a CPA if you have several IRAs.