Roth IRA calculator
Put 6,500 into a Roth IRA every year for 30 years at 7% and the balance reaches 613,995.11, of which 418,995.11 is tax-exempt growth. Deposits above the 2026 limit are refused. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Annual contribution
- 6,500
- Years
- 30
- Rate percent
- 7
- Rate decimal
- 0.07
- Current balance
- 0
- Tax year
- 2,026
- Contribution limit
- 7,500
A Roth IRA is funded with after-tax dollars, and qualified withdrawals of both contributions and earnings are tax-free. This Roth IRA calculator projects that future tax-free balance from an annual contribution, an expected annual rate of return as a percent, and the number of years the account stays invested. It compounds end-of-year deposits with the ordinary-annuity future-value identity and optionally grows a starting Roth balance for the full horizon. Results are educational illustrations, not tax advice or a guarantee of market returns.
What a Roth IRA tax-free projection means and how the balance is built
A Roth individual retirement account is funded with after-tax dollars. Qualified withdrawals of both the contributions and the earnings are tax-free, which is the search intent behind a Roth IRA calculator: not merely how much the account will hold, but how much tax-free wealth these annual deposits become. This capability answers that compounding question with a closed form.
When the expected return is exactly zero there is no compounding, the annuity factor would divide by zero, and the identity collapses to P plus C times n — cash stacked, nothing grown. Contributions are treated as an ordinary end-of-year annuity, the usual illustration in retirement-plan textbooks. Use this identity for long-run Roth illustrations, catch-up scenarios at age fifty, and classroom time-value problems that ask for a Roth nest egg.
Do not use it for MAGI phaseouts, intra-year dollar-cost averaging, sequence-of-returns risk, or the five-year and age-fifty-nine-and-a-half qualified-distribution tests — those need a period-by-period schedule or a tax engine, not a closed form.
Who relies on a Roth IRA projection
The query is not the same as a generic IRA growth calculator: people who type Roth IRA want the after-tax, tax-free-withdrawal story and they want the IRS dollar cap enforced, not a projection that quietly accepts nine thousand dollars in a year the law allows seven thousand five hundred. Employers and benefits portals can project a payroll-deducted Roth IRA at a stated expected return so employees see the decades-ahead tax-free number next to this year's deposit, with over-limit input rejected instead of silently illustrated.
Classrooms and exam-prep generators need a deterministic oracle that handles a zero rate without dividing by zero, names the 2026 legal limit in the error, and returns contributed cash versus tax-free growth separately. Keep requests small. This tool does not apply MAGI income-phaseout rules, required minimum distributions, inflation, or the five-year qualified-distribution clock — it projects a constant-rate Roth balance inside the annual dollar cap only.
Pair it with your own income tests when the question is whether the saver may contribute at all, not what a known legal deposit stream will grow into.
What you can do with it
Long-horizon Roth IRA illustration
Project the tax-free nest egg from this year's contribution, a starting Roth balance, and a long-run expected return so a saver can see cash deposited versus tax-free growth.
Age-50 catch-up and limit checks
Pass age 50 or older to raise the legal cap to the 2026 catch-up limit, or omit age and let over-limit contributions fail instead of publishing an illegal projection.
FAQ
What is the legal Roth IRA contribution limit?
For tax year 2026 the IRS dollar cap is 7500 under age 50 and 8600 at age 50 or older. This calculator uses those constants. MAGI phaseouts are not applied.
What happens if the annual contribution exceeds the legal limit?
Under-50 requests that omit age are checked against 7500; pass age 50 or older to use the 8600 catch-up limit.
Are contributions assumed at the start or the end of each year?
At the end of each year (an ordinary annuity). That is the usual closed form in Roth IRA illustrations. A beginning-of-year stream would earn one extra period of interest on every deposit and is a different identity.
How much will 6,500 a year be worth in a Roth IRA after 30 years?
At a steady 7% a year and no starting balance, it reaches 613,995.11. You put in 195,000 yourself; the other 418,995.11 is growth you can take out without tax once the qualified-withdrawal rules are met.
Does this calculator check whether my income lets me contribute to a Roth IRA?
No. It does not apply the income phaseout rules, required minimum distributions, inflation or the five-year waiting rule. It shows how a deposit you are already allowed to make would grow at a constant rate, so check eligibility separately.
Related tools
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/fin/roth-ira \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"annual_contribution":6500,"rate_percent":7,"years":30}'const res = await fetch("https://api.kit.forhosting.com/fin/roth-ira", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"annual_contribution": 6500,
"rate_percent": 7,
"years": 30
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/fin/roth-ira",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"annual_contribution": 6500,
"rate_percent": 7,
"years": 30
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/fin/roth-ira", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"annual_contribution":6500,"rate_percent":7,"years":30}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"annual_contribution":6500,"rate_percent":7,"years":30}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/fin/roth-ira", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"annual_contribution": 6500,
"rate_percent": 7,
"years": 30
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "fin.roth_ira",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Limits
max_years | 80 |
max_contribution | 8600 |
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |
Technical notes
Unlike a generic IRA growth tool, it enforces the IRS 2026 contribution dollar limit — seven thousand five hundred dollars under age fifty, eight thousand six hundred with the age-fifty catch-up — and rejects any contribution above the legal cap with invalid_input so an over-contribution never becomes a published projection.
What a Roth IRA tax-free projection means and how the balance is built
If the account starts at current_balance P, defaulting to zero, receives the same annual contribution C at the end of every year, and earns a constant expected annual rate r for n years, the projected tax-free balance is P times one plus r to the n, plus C times one plus r to the n minus one, all divided by r. A worked check is six thousand five hundred contributed each year for thirty years at seven percent with no starting balance: the annuity factor is about 94.461 and the projected Roth sits near six hundred fourteen thousand, all framed as tax-free if qualified-distribution rules are later met.
Input contract, IRS legal limit, formula, and response fields
Optionally set age to an integer from zero through one hundred twenty: when age is fifty or older the 2026 catch-up legal limit of eight thousand six hundred applies, otherwise the under-fifty limit of seven thousand five hundred applies. Omitting age uses the under-fifty cap. Age is present only when you sent it. Money-like fields use half-up rounding once from the raw floating-point results so goldens stay byte-stable across runtimes. POST a JSON body with three required finite numbers. annual_contribution is the yearly Roth deposit, with aliases contribution and contribution_amount; it must be strictly greater than zero and must not exceed the IRS legal dollar limit for tax year 2026. rate_percent is the expected annual return as a percent so that seven means seven percent per year, not a decimal fraction, with aliases rate, expected_return, and return_rate; it must be greater than negative one hundred and at most fifty so that one plus r stays positive and one plus r to the n stays finite. years is a whole number of compounding years from one through eighty, with aliases n and nper. Optionally set current_balance, with aliases balance, principal, and starting_balance, to the Roth value already on the books; it defaults to zero and must be non-negative. The engine forms r as rate_percent over one hundred, compounds the principal as current_balance times one plus r to the years, and grows the contribution stream as annual_contribution times one plus r to the n minus one over r, or annual_contribution times years when r is zero. total_contributed is current_balance plus annual_contribution times years; tax_free_growth is future_value minus total_contributed, the earnings that leave the Roth tax-free if the withdrawal is qualified. The response echoes the rounded inputs plus tax_year, contribution_limit, catch_up_applied, future_value, those cash fields, rate_decimal, and a short formula string. A contribution above the legal limit, missing fields, empty strings, non-finite values, a non-positive contribution, a negative balance, non-integer or out-of-range years or age, and a rate at or below negative one hundred or above fifty fail with invalid_input and are not billed.
Where a Roth IRA calculator API earns its keep
Advisors and robo-onboarding flows use the endpoint as a first-pass illustration before collecting MAGI or filing status: sweep years or rate_percent from your own code to build a family of scenarios, pin future_value and tax_free_growth in tests, and show how a catch-up contribution at age fifty changes the nest egg without standing up a full Monte Carlo engine.
Integration use cases
Advisor, benefits, and classroom oracles
Sweep years or rate_percent to build scenario tables, pin future_value in tests, and reject illegal deposits without a Monte Carlo engine or a spreadsheet per household.
Technical questions
How does the Roth IRA calculator project the tax-free future value?
With r = rate_percent/100 and n = years: future_value = current_balance × (1+r)^n + annual_contribution × [((1+r)^n − 1)/r]. When the rate is zero, future_value = current_balance + annual_contribution × years. The API also returns total_contributed and tax_free_growth, the earnings that leave a qualified Roth tax-free.
What does the Roth IRA calculator cost?
The browser tool is free. API requests use prepaid KIT balance at $0.002 per successful call; invalid input is not billed.