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RD Calculator
An RD calculator works out what a recurring deposit — a regular monthly savings plan — will be worth when it matures. Enter the amount you deposit each month, the annual interest rate, and how long you will keep saving, and it shows your maturity value, how much you deposited in total, and how much of the result is interest.
Deposits are made at the beginning of each month. Interest is added monthly, every 3 months, or every 12 months, depending on the frequency you pick.
| Maturity value | |
| Total deposited | |
| Interest earned | |
| Tenure | |
| Interest share of maturity value |
Year-by-year breakdown
| Year | Deposited so far | Balance | Interest so far |
|---|
How it works
A recurring deposit is a simple deal: you put in the same amount every month, the account adds interest to your growing balance, and at the end of the period you take out everything — your deposits plus the interest. The key difference from a lump-sum investment is that the money goes in month by month. That is the whole point of this calculator: it grows a stream of monthly deposits, not a single starting amount. A calculator that only grows a lump sum cannot answer this question, because an early deposit earns interest for years while the last deposit earns interest for only a month.
Each input does one job. Monthly deposit is the fixed amount you save every month. Annual interest rate is the rate the account pays each year, as a percentage. Tenure is how long the plan runs, in years plus extra months. Compounding frequency is how often interest is added to your balance: every month, every three months, or once a year. More frequent compounding gives a slightly higher result, because interest starts earning interest sooner.
Deposits are assumed to be made at the beginning of each month, so each deposit earns interest for its full month. With monthly compounding, the maturity value follows the standard formula for a series of deposits made at the start of each period.
For quarterly compounding, the same month-by-month idea applies, but interest is added every three months at the quarterly rate (annual rate ÷ 4 ÷ 100), and for annual compounding it is added every twelve months at the annual rate. That is an approximation, and the page says so plainly: real accounts can work out the timing of interest slightly differently, and a partial final period — for example, a plan of 14 months with quarterly compounding — earns no interest on its last two months under this method, because no compounding date falls inside them. The year-by-year table shows your balance at the end of each year, so you can see the growth step by step.
Two things are worth remembering. First, the interest is the smallest part of the result in a short plan and the largest part in a long one. In the worked example below, a two-year plan earns only about $312 of interest on $4,800 deposited, but over ten years at the same rate the interest would be a much bigger share — that is compounding doing its slow work. Second, the result assumes the rate never changes and every deposit is made on time. A missed deposit, a fee, or a rate change will all move the real result away from this estimate.
Worked example
Sam deposits $200 every month for 24 months (2 years) at 6% a year, compounded monthly, with each deposit made at the beginning of the month.
Step 1: Find the monthly rate and the number of months. The monthly rate is 6% ÷ 12 = 0.5% (0.005), and the plan runs for n = 24 months.
Step 2: Apply the formula. Maturity value = $200 × [((1.005)24 − 1) ÷ 0.005] × 1.005 = $200 × 25.4319 × 1.005 = $5,111.82.
Step 3: Work out what Sam put in. Total deposited = $200 × 24 = $4,800.00.
Step 4: Work out the interest. Interest earned = $5,111.82 − $4,800.00 = $311.82.
Enter the same numbers — $200 a month, 6%, 2 years, monthly compounding — and the calculator shows exactly the same result: a maturity value of $5,111.82, made up of $4,800.00 deposited and $311.82 of interest. Try raising the tenure to 5 years and watch the interest share grow: the deposits rise in a straight line, but the balance curves upward as interest compounds.
FAQ
What is a recurring deposit?
A recurring deposit is a savings plan where you put in a fixed amount every month for a fixed period, and the account pays interest on the growing balance. At the end of the period you get back everything you deposited plus the interest it earned — that total is the maturity value. It is a way to save a little at a time instead of needing a large lump sum up front.
How is the maturity value calculated?
With monthly compounding and deposits at the beginning of each month, the maturity value is P × [((1 + i)^n − 1) ÷ i] × (1 + i), where P is the monthly deposit, i is the monthly interest rate (annual rate ÷ 12 ÷ 100), and n is the number of months. Each deposit earns interest for a different length of time, and the formula adds all of them up. For quarterly or annual compounding, interest is added every three or twelve months instead, using the rate for that period.
Does the deposit timing (start vs end of month) matter?
Yes, a little. This calculator assumes each deposit is made at the beginning of the month, so it earns interest for the full month. If you deposit at the end of the month instead, each deposit earns interest for one month less, and the maturity value is slightly lower — the difference is one month of interest on the total deposited. Check with your account provider which timing applies to your plan.
What happens if I miss a deposit?
If you miss a deposit, less money goes into the account, so the maturity value will be lower than the calculator shows — roughly the missed deposit plus the interest it would have earned. Some accounts also charge a late fee or reduce the interest rate for missed deposits, so check your account's rules. To see the effect, run the calculator again with a smaller monthly deposit or a shorter tenure.
Is the interest guaranteed?
It depends on the account. A fixed-rate deposit account pays the rate it promises for the whole period, so the maturity value is known in advance. A variable-rate or market-linked account can pay more or less, so the result here is only an estimate. This calculator assumes the rate stays constant and that every deposit is made on time.