Fixed deposit calculator
Deposit 100,000 at 7.5% for 5 years, compounded quarterly, and it matures at 144,994.8, with 44,994.8 of interest. Compare monthly, quarterly, half-yearly or annual compounding on the same deposit. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Principal amount
- 100,000
- Annual rate
- 7.5
- Tenure
- 5
- Compounding
- Quarterly
- Compounds per year
- 4
- Maturity value
- 144,994.8
- Interest earned
- 44,994.8
A fixed deposit locks a lumpsum at a published annual rate for a stated tenure and returns that principal plus compounded interest on the maturity date.
How a fixed deposit compounds to its maturity amount
A bank fixed deposit—also called a term deposit in some markets—is a lumpsum you place with an issuer at a published annual nominal rate for a locked tenure measured in years. When the bank compounds n times per year, each period earns r divided by n, and there are n times tenure such periods, so the closed form is maturity value equals P times one plus r over n, raised to n times tenure.
That is the same compound-interest identity textbooks write as A equals P times (1 plus r over n) to the n t, and it is how a bank turns a 7.5 percent five-year quarterly fixed deposit into a maturity credit larger than simple interest of P times r times tenure. The four accepted schedules map to n as follows: annual is one, half-yearly is two, quarterly is four, and monthly is twelve.
Quarterly compounding is the schedule most retail banks publish for cumulative FDs; monthly is common on shorter tenures; half-yearly and annual appear on older product sheets and on some credit-union term deposits. When the annual rate is exactly zero the power collapses to the honest special case maturity value equals P, so a promotional zero-rate placeholder does not invent interest. Money fields round to two decimal places so they match currency.
Interest earned is maturity value minus principal. This calculator models a cumulative deposit that reinvests interest until maturity; it does not credit a separate payout stream.
What you can do with it
Bank and credit-union FD rate pages
Turn a quoted annual rate, compounding schedule, and tenure into the fixed-deposit maturity amount a saver will receive if they hold to the end.
Compare compounding schedules on the same lumpsum
Line up monthly, quarterly, and half-yearly offers on the same principal and tenure and rank them by maturity value, not by the headline rate alone.
FD ladder and household planning
Price each rung of a ladder—or a single six-month lock-up at tenure 0.5—and store the same cents the free browser preview already showed.
FAQ
What happens if the tenure is zero, negative, or missing?
Tenure must be a finite number of years greater than zero. Zero, negatives, booleans, empty strings, and non-numeric values are rejected and not billed.
How do I enter a 6-month or 18-month fixed deposit?
Tenure is measured in years. A 6-month FD is tenure 0.5 and an 18-month FD is tenure 1.5. Pair that tenure with the issuer's compounding frequency.
Does this include tax deducted at source or a premature-withdrawal penalty?
No. This calculator assumes the deposit is held to maturity as a cumulative instrument and returns only the compounded maturity amount and interest earned. Withholding and early-break haircuts are a different search and a different tool.
How is the fixed deposit maturity amount calculated?
Divide the annual rate by the number of compounding periods per year, add one, raise it to the number of periods in the tenure and multiply by the principal. With a zero rate, the maturity amount simply equals the principal.
Does the compounding frequency change what I receive?
Yes. The same headline rate gives a different maturity amount when interest is compounded monthly, quarterly, half-yearly or annually. Line up offers on the same principal and tenure and compare them by maturity value, not by the rate alone.
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/fixed-deposit \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"principal":100000,"annual_rate":7.5,"tenure":5,"compounding":"quarterly"}'const res = await fetch("https://api.kit.forhosting.com/fin/fixed-deposit", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"principal": 100000,
"annual_rate": 7.5,
"tenure": 5,
"compounding": "quarterly"
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/fin/fixed-deposit",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"principal": 100000,
"annual_rate": 7.5,
"tenure": 5,
"compounding": "quarterly"
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/fin/fixed-deposit", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"principal":100000,"annual_rate":7.5,"tenure":5,"compounding":"quarterly"}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"principal":100000,"annual_rate":7.5,"tenure":5,"compounding":"quarterly"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/fin/fixed-deposit", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"principal": 100000,
"annual_rate": 7.5,
"tenure": 5,
"compounding": "quarterly"
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "fin.fixed_deposit",
"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.
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
The cash you actually receive is not the headline rate times years: it depends on how often the issuer compounds—annually, half-yearly, quarterly, or monthly. This fixed deposit calculator takes principal, annual interest rate as a percent, tenure in years, and compounding frequency, applies the closed-form compound-interest identity, and returns the maturity value together with the interest earned. Tenure that is not a positive number of years fails with invalid_input and is not billed.
How a fixed deposit compounds to its maturity amount
Convert the percent to a decimal rate r equal to annual_rate divided by one hundred.
Input contract, response shape, and error behaviour
Tenure is the field the product contract singles out: zero, a negative lock-up, or a non-numeric stand-in is never treated as a reverse-time deposit or as a silent zero-horizon. POST a JSON body with four required fields. principal is the opening deposit as a finite number greater than zero (aliases amount and deposit). annual_rate is the annual nominal interest as a percent such as 7.5 for seven and a half percent per year, finite, at least zero, and at most one thousand (aliases rate and interest_rate). tenure is the lock-up in years as a finite number greater than zero and at most one hundred; a six-month fixed deposit is tenure 0.5 and an eighteen-month deposit is tenure 1.5 (aliases years and term). compounding is one of the closed set annual, half_yearly, quarterly, or monthly (aliases frequency and compounds). Each numeric field may arrive as a JSON number or as a numeric string. Missing fields, empty strings, booleans, non-finite values, a non-positive principal, a negative annual_rate, a non-positive tenure, and any compounding value outside the enum fail with invalid_input naming the field and are not billed. On success the body echoes principal, annual_rate, tenure, and compounding, and adds compounds_per_year, maturity_value, interest_earned, and a formula string restating the discrete identity and the zero-rate collapse. Example: principal one hundred thousand, annual_rate 7.5, tenure five, compounding quarterly yields n equals four and a maturity value equal to one hundred thousand times 1.01875 to the twentieth, rounded to cents. This endpoint does not model premature-withdrawal penalties, tax withheld at source, non-cumulative interest paid out to a savings account, or senior-citizen rate add-ons; it computes hold-to-maturity cumulative compound interest only.
Where a fixed deposit calculator earns its keep
Educators teaching discrete compounding can seed classroom examples that fail loudly when tenure is not a positive number of years, instead of plotting a nonsense curve through a zero or negative horizon. Failed validation does not consume balance. Keep principal positive, tenure in years and strictly greater than zero, and compounding inside the enum, pin the rounded money fields in tests, and you get reproducible fixed-deposit maturities for widgets, LMS modules, and edge workers without a deposit-origination stack of your own. Comparison tables that line up a one-year monthly FD against a five-year quarterly FD can call the same pure module from the browser for free previews and from the API when storing a scenario, guaranteeing that the maturity a visitor saw matches the maturity stored after they save a quote. Household planners who already know the cash they can lock can post principal, annual_rate, tenure, and compounding to fill a card with maturity value and interest earned, then decide whether stretching from two years to five years is worth the extra lock-up. Product teams building an FD ladder can request several tenures with the same principal and rate and read interest_earned on each rung without writing their own power function.
Technical questions
How is fixed-deposit maturity calculated from principal, rate, tenure, and compounding?
Send principal (>0), annual_rate as a percent (≥0), tenure in years (>0), and compounding as annual, half_yearly, quarterly, or monthly. The calculator uses maturity_value = P·(1+r/n)^(n·t) with r = annual_rate/100. Interest earned is maturity value minus principal.
What does a fixed-deposit maturity calculation cost on the API?
The browser tool is free. API requests use prepaid KIT balance at $0.002 per successful call; invalid input is not billed.