Roth IRA Calculator
See how after-tax Roth IRA contributions grow completely tax-free by retirement.
Results update as you type.
About this calculator
A Roth IRA is funded with after-tax dollars, so qualified withdrawals in retirement — both your contributions and all investment growth — come out completely tax-free. This Roth IRA calculator grows your starting balance and annual contributions at your expected return to retirement, then compares the tax-free result with an equivalent traditional account taxed at withdrawal, so you can weigh paying tax now against paying it later.
Each year it adds your contribution and applies the annual return to the balance. For example, a 30-year-old starting with 5,000 and adding 7,000 a year at 7% until age 65 ends with about 1.02 million, of which roughly 250,000 is contributions and 770,000 is tax-free growth. If a traditional account held the same balance and withdrawals were taxed at 22%, you would keep only about 796,000 — the gap is the Roth advantage.
Use it to project a tax-free retirement pot and to judge whether a Roth beats a traditional IRA for your situation. The Roth wins when your tax rate in retirement is the same or higher than today, because you lock in today’s rate on the seed rather than the much larger harvest.
Frequently asked questions
Why is a Roth IRA tax-free?
You contribute money you have already paid income tax on, so the IRS does not tax it again. Once the account is at least five years old and you are over 59½, every withdrawal — contributions and growth alike — comes out completely tax-free.
Roth or traditional IRA — which is better?
A Roth wins when your tax rate in retirement is the same or higher than today, since you lock in today’s lower rate. A traditional IRA can win if you expect a much lower rate in retirement. The "traditional after tax" line shows the comparison.
What is the Roth IRA contribution limit?
The IRS sets an annual limit — 7,000 for 2024, or 8,000 if you are 50 or older — which the calculator uses as its default contribution. High earners may be phased out of contributing directly once their income exceeds set thresholds.
When can I withdraw from a Roth IRA tax-free?
Qualified tax-free withdrawals require the account to be at least five years old and you to be over 59½. You can always take out your own contributions tax- and penalty-free, but withdrawing growth early can trigger taxes and a penalty.
Roth IRA or 401(k) — which should I fund first?
A common order is to contribute enough to a 401(k) to get the full employer match first, since that is free money, then fund a Roth IRA for its tax-free growth and wider investment choice. This tool models the Roth side of that plan.
Does the Roth advantage depend on my tax rate?
Yes. Paying tax now (Roth) beats paying later (traditional) when your retirement tax rate is equal to or higher than today’s. The comparison here taxes the traditional balance at the retirement tax rate you enter, so lowering that rate is what narrows the Roth’s edge.
API — use this calculator from code
Call this calculator as a free JSON endpoint — no key required. Send the field values below as query parameters or JSON. Read the full API docs →
Endpoint
GET https://calculator.free/api/v1/roth-ira/curl
curl "https://calculator.free/api/v1/roth-ira/?current_age=30&retire_age=65&starting=5000&contribution=7000&return_rate=7"JavaScript fetch()
const r = await fetch(
"https://calculator.free/api/v1/roth-ira/?" + new URLSearchParams({
"current_age": "30",
"retire_age": "65",
"starting": "5000",
"contribution": "7000",
"return_rate": "7"
}));
const data = await r.json();
console.log(data.results);Results are estimates for general guidance only, not financial, medical or tax advice.