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Saving calculator

RD Calculator

A recurring deposit builds a lump sum out of a monthly habit. The interest looks modest against the total deposited — this explains why that is arithmetic rather than a bad rate.

Your numbers

₹10010 thousand₹5L
1%12%

That is 5 years.

6 mo120 mo
Compounding frequency

Maturity value

₹7,15,542

Your first instalment earns interest for 5 years. Your last earns it for one month — which is why the interest looks small against the total deposited.

Total deposited
₹6,00,000
Interest earned
₹1,15,542
Instalments
60

How the balance builds

Deposits stack in a straight line. Interest curves upward as the balance grows.

  • Deposited
  • Interest

Year by year

Cumulative deposits, interest and balance at each year-end.

Yearly recurring deposit growth
YearDepositedInterestBalance
Year 1₹1,20,000₹4,487₹1,24,487
Year 2₹2,40,000₹17,658₹2,57,658
Year 3₹3,60,000₹40,118₹4,00,118
Year 4₹4,80,000₹72,515₹5,52,515
Year 5₹6,00,000₹1,15,542₹7,15,542

The arithmetic

How this calculator works

No proprietary model, no adjustment factor we will not name. This is the standard formula, applied exactly as written.

Each instalment earns for the time it stays on deposit: M = Σ P × (1 + r ÷ 400)^((n − k + 1) ÷ 3) k=1..n where the k-th instalment remains on deposit for (n − k + 1) months, and quarterly compounding means three months to a compounding period.
P
Monthly instalment
r
Annual rate as a percentage
n
Number of instalments
k
Which instalment — 1 is the first
M
Maturity value
  • Summing every instalment separately is exact and, more usefully, transparent — you can see precisely why the last instalment contributes almost nothing in interest.
  • The divisor of 400 is the quarterly rate: the annual percentage divided by 100 to make it a decimal, then by 4 for the quarter.

Worked example

The same maths, on real numbers

₹10,000 a month for five years at 6.8%, compounded quarterly.

Worked example inputs and results
Monthly instalment₹10,000
Rate6.8% p.a.
Tenure60 months
Total deposited₹6,00,000
Interest earned₹1,15,542
Maturity value₹7,15,542

Interest is about 19% of what you put in, which looks thin next to a lump-sum FD at the same rate. The reason is simple: your first instalment earns for sixty months, your last for one, and the average across all sixty is roughly thirty. An RD is not a weaker product than an FD — it is the same product used by someone who does not have the lump sum yet, and that is exactly who it is for.

What this calculator assumes

  • Every instalment is paid on time. Missed instalments usually attract a small penalty and reduce the maturity value.
  • Interest compounds quarterly, the standard for bank recurring deposits.
  • The rate is fixed at booking and applies for the full tenure, even if rates move afterwards.
  • Figures are gross, before tax.

What it deliberately leaves out

  • TDS and slab-rate tax on the interest are not deducted.
  • Post office RDs use a slightly different convention and a rate set by the government each quarter — figures there may differ a little.
  • Premature closure penalties are not modelled.

Questions about the recurring deposit calculation

It depends entirely on when you need the money. For a goal within three years an RD is usually right — the amount and date are certain, which is what a near-term goal requires. For anything beyond five years an RD's post-tax return is unlikely to beat inflation, and a SIP into a suitable fund gives you a better chance, at the cost of certainty.

Most banks charge a small penalty per missed instalment and may close the account after a run of defaults. The maturity value also drops, since that money never went in. Setting up a standing instruction on salary day removes the problem entirely.

Have the numbers?

You have the numbers. Now build the plan.

A calculator answers one question well. A plan decides which questions are worth asking in the first place — and in what order.