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Savings Plan Maturity

The first deposit earns interest for the whole term while the last earns almost none, which is why an instalment plan pays roughly half what a lump-sum deposit at the same rate would.

Your numbers

Final amount

19,154,417

Total deposited

18,000,000

Interest

1,154,417

Formula

Final amount = Σ Monthly deposit × (1 + r) ^ n, r = Annual rate ÷ 1200

The interest shown is before tax — Korean interest income tax of 15.4% reduces what you actually receive.

What to enter

InputDefaultAccepted range
Monthly depositThe amount you pay in every month.500,0000 and up
Annual rate (%)Interest quoted per year; the monthly rate is this over 12.40 and up
Months (mo)The period counted in months; a yearly rate gets divided by twelve.361 and up

Step by step

FormulaFinal amount = Σ Monthly deposit × (1 + r) ^ n, r = Annual rate ÷ 1200
With the default numbersFinal amount = Σ 500,000 × (1 + r) ^ n, r = 4 ÷ 1200
AnswerFinal amount = 19,154,417

Quick reference table

Results when only Monthly deposit changes and everything else stays put.

Monthly depositFinal amountTotal depositedInterest
250,0009,577,2099,000,000577,209
375,00014,365,81313,500,000865,813
500,00019,154,41718,000,0001,154,417
750,00028,731,62627,000,0001,731,626
1,000,00038,308,83436,000,0002,308,834

What each result means

ResultAt default values
Final amountPrincipal plus interest — what you get at the end.19,154,417
Total depositedEverything you paid in over the period, interest not included.18,000,000
InterestThe interest earned or owed over the period.1,154,417

Common mistakes

The interest shown is before tax — Korean interest income tax of 15.4% reduces what you actually receive.

Glossary

Monthly deposit
The amount you pay in every month.
Annual rate
Interest quoted per year; the monthly rate is this over 12.
Months
The period counted in months; a yearly rate gets divided by twelve.
Final amount
Principal plus interest — what you get at the end.
Total deposited
Everything you paid in over the period, interest not included.
Interest
The interest earned or owed over the period.

Frequently asked questions

Q. How is Savings Plan Maturity calculated?

Final amount = Σ Monthly deposit × (1 + r) ^ n, r = Annual rate ÷ 1200 — The first deposit earns interest for the whole term while the last earns almost none, which is why an instalment plan pays roughly half what a lump-sum deposit at the same rate would.

Q. Can you walk through an example?

With Monthly deposit 500,000, Annual rate 4%, Months 36mo, the answer is Final amount 19,154,417.

Q. What do I need to enter?

Enter Monthly deposit, Annual rate, Months. The result recalculates as you type, and an empty box counts as zero.

Q. How much does the answer move if I change a number?

Changing only Monthly deposit moves the answer to Monthly deposit 250,000 → Final amount 9,577,209 and Monthly deposit 1,000,000 → Final amount 38,308,834. The table below lays out five steps.

Q. How are the numbers rounded?

Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.

Q. Anything to watch out for?

The interest shown is before tax — Korean interest income tax of 15.4% reduces what you actually receive.

Related calculators

Tax rates and interest conventions differ by country and product — check your contract for real transactions.