| Field | Value |
|---|---|
| {{ row.label }} | {{ row.display }} |
| Period | Credit window | Days | Opening ($) | Gross ($) | Tax ($) | Paid out ($) | Ending ($) |
|---|---|---|---|---|---|---|---|
| {{ row.periodNumber }} | {{ row.windowLabel }} | {{ row.days }} | {{ formatMoney(row.openingBalance) }} | {{ formatMoney(row.grossInterest) }} | {{ formatMoney(row.taxApplied) }} | {{ formatMoney(row.paidOut) }} | {{ formatMoney(row.endingBalance) }} |
| Year | Gross ($) | Tax ($) | Paid out ($) | Ending ($) | Total value ($) |
|---|---|---|---|---|---|
| Year {{ row.yearIndex }} | {{ formatMoney(row.grossInterest) }} | {{ formatMoney(row.taxApplied) }} | {{ formatMoney(row.paidOut) }} | {{ formatMoney(row.endingBalance) }} | {{ formatMoney(row.totalAfterTaxValue) }} |
A fixed deposit is a lump-sum savings product that trades access to cash for a stated rate and a stated term. That sounds simple, but the number that matters in practice is not just the advertised rate. Compounding frequency, taxes on interest, and inflation all change what the deposit is worth by the time it matures.
This calculator turns that tradeoff into a result you can inspect rather than assume. It starts with one principal amount, applies a nominal annual rate across the selected tenure, and then shows the maturity amount, net interest, tax drag, inflation-adjusted value, annual and monthly schedules, three chart views, and a JSON export of the scenario.
That makes it useful when you are comparing tenures, checking whether more frequent crediting actually changes the outcome much, or testing whether an apparently safe return still preserves purchasing power after tax and inflation. A one-year deposit and a three-year deposit can both look tidy in a rate table, but they can tell very different stories once you annualize the result and discount it back to real value.
The package is also more specific than a generic compound-interest worksheet. It keeps a year-end schedule, a month-by-month schedule, a principal-versus-interest breakdown chart, a balance-growth chart, and a cumulative-interest timeline, so you can see not only the ending figure but the path the model takes to get there.
There is an important boundary, though. The calculator models a single deposit held to term. It does not model additional contributions, early-withdrawal penalties, rate changes, auto-renewal terms, or bank-specific tax handling. Use it as a planning estimate, then compare the result with the actual deposit disclosure before treating it as a product quote.
A reliable first pass is to ignore taxes and inflation, enter the deposit amount, the stated annual rate, the term, and the compounding frequency, and read the result as a gross growth comparison. Once that baseline looks sensible, add the tax rate on interest and the inflation rate to see how much of the headline growth survives in spendable terms.
Treat the effective annual yield as a comparison aid, not as a promise of a bank disclosure number. The calculator annualizes its own modeled outcome, while real deposit products can apply disclosure conventions, penalties, withholding, and maturity handling that are outside this model.
The model begins with a single principal and a nominal annual rate. The selected compounding frequency maps to a number of months per crediting event: 12 for annual, 6 for semi-annual, 3 for quarterly, and 1 for monthly. The tenure is assembled from whole years plus months, with years floored to an integer and months clamped to the 0 to 11 range.
The important implementation detail is that interest is only added on completed compounding boundaries. The calculator walks month by month through the term, but it credits interest only when the current month lands exactly on the chosen interval. If a term ends between crediting dates, the remaining partial period stays flat. That is why a 17-month quarterly deposit earns five full quarterly credits and then stops, rather than earning a prorated sixth-quarter amount.
You can summarize the package logic with a gross-balance pass followed by a tax and inflation pass.
| Symbol | Meaning in this calculator | Source |
|---|---|---|
P |
Initial one-time deposit | Principal |
rann |
Nominal annual interest rate | Interest rate |
pm |
Months per compounding event | Compounding frequency |
t |
Tax rate applied to total earned interest | Tax rate (interest) |
i |
Average annual inflation used for real-value adjustment | Inflation rate |
M |
After-tax maturity amount | Derived |
Mreal |
Inflation-adjusted maturity amount | Derived |
The schedules and the charts are built from the gross credited balance, not from the after-tax maturity amount. The calculator first accumulates all credited interest, records the annual and monthly balance path, and only then applies the tax rate to total interest to produce the headline maturity amount and the net-interest figure. That means the schedule can end at a larger number than the summary whenever tax is non-zero.
| Output | What it tells you |
|---|---|
| Deposit Summary | The full scenario in one place, including term, compounding periods, tax on interest, real maturity, and effective annual yield. |
| Annual Schedule | Gross cumulative interest and ending balance at each year boundary and at the final partial year. |
| Monthly Schedule | Gross cumulative interest and ending balance for every month in the tenure, including flat months between crediting events. |
| Balance Breakdown | The share of the after-tax maturity amount that is still principal versus net interest. |
| Balance Growth | Year-end gross balance growth across the term. |
| Interest Timeline | Gross cumulative interest by month, which makes stepwise crediting easy to spot. |
| JSON | A structured export of inputs, derived results, and both schedules. |
All calculations happen in the browser. Copy and download actions generate CSV, DOCX, image, or JSON files locally and do not rely on server-side processing.
Enter a principal of $10,000, an annual rate of 4.00%, a term of 3 years, and Quarterly compounding. The calculator returns a maturity amount of $11,268.25, net interest of $1,268.25, and an effective annual yield of about 4.0604%.
The annual schedule ends year 1 at $10,406.04, year 2 at $10,828.57, and year 3 at $11,268.25. The monthly schedule stays flat in months 1, 2, 4, 5, and similar gaps, then steps upward when each quarter closes.
Keep the same deposit but add a 20% tax rate on interest and 3% inflation. Gross credited interest is still $1,268.25, but the headline maturity amount drops to $11,014.60 because only $1,014.60 of that interest remains after tax.
The inflation-adjusted maturity falls further to about $10,079.92, and the effective annual yield drops to about 3.2737%. This is the run that shows why headline growth and real value are not the same thing.
Use $10,000 at 4.00% for 1 year and 5 months with quarterly compounding. The calculator returns a maturity amount of $10,510.10, which reflects five completed quarterly credits rather than a prorated final partial quarter.
In the monthly schedule, months 16 and 17 remain at the same ending balance as month 15. That is the intended behavior of this model and a useful reminder to check how the actual deposit handles incomplete final periods.
Because the calculator records every month but only credits interest at the chosen compounding interval. With quarterly compounding, for example, the balance changes in months 3, 6, 9, and so on.
The schedule tracks the gross credited balance. Tax is applied afterward to total earned interest, so the summary becomes smaller while the schedule remains unchanged.
Not necessarily. The calculator annualizes its own modeled result and can include tax drag, while a bank’s disclosed annual percentage yield follows disclosure rules and the product’s specific terms.
No. It models one deposit held to maturity with no interim cash flows and no penalty logic.