Savings Calculator
How much will you have if you save every month? Get your maturity amount — gross interest, tax taken out, net in hand — in seconds. Works in any currency.
Interest method
Maturity amount (net in hand)
Some values were above the allowed range and were capped for this calculation.
Deposits are assumed at the start of each month (annuity-due), interest compounds monthly.
Every calculation runs in your browser — nothing is sent to a server.
How this savings calculator projects your balance
This tool estimates what a savings plan grows to over a fixed term, combining an optional starting balance, a regular monthly deposit, an interest rate, and the tax taken from interest. It is a planning estimate to help you compare options — not financial advice, and not a quote from any bank. Real accounts differ in how they count days and credit interest, so treat the result as a close approximation rather than a guaranteed figure.
Simple versus compound interest
With simple interest, each deposit earns the same flat rate on its original amount until the term ends. With monthly compound interest, the interest you have already earned itself starts earning interest, so later months grow a little faster. The gap is small over a few months and widens over years. The calculator assumes deposits are made at the start of each month (an annuity-due), which means every deposit earns one extra period of interest compared with end-of-month timing.
How after-tax interest is found
Most places tax the interest savings earn. The tool works out the interest first, then withholds tax at the rate you enter, and reports the net interest you actually keep. Korea's deposit tax of 15.4% (14% income tax plus a 1.4% local surtax) is offered as a preset; enter 0% for a tax-free account, or any other rate to match your own country.
| Same 2-year plan | Simple interest | Monthly compound |
|---|---|---|
| Total deposited | 12,000,000 | 12,000,000 |
| Interest before tax | ~437,500 | ~447,400 |
| Interest after 15.4% tax | ~370,100 | ~378,500 |
Why your bank statement may differ
Small assumptions explain most gaps between this estimate and a real account. The calculator credits deposits on the first of the month, compounds monthly, and rounds to whole units; a bank may use a daily day-count, credit interest on the exact date each deposit lands, pay interest only at maturity, or round differently. A lump sum left untouched for the whole term also earns more than the same total spread across monthly deposits, because it is invested for longer — you can model that by putting the amount in the starting balance instead.
Using it well — and its limits
To compare a savings plan against a lump sum, put recurring money in the monthly deposit and one-off money in the starting balance, then read the two side by side. The tool does not model rate changes mid-term, early-withdrawal penalties, inflation, or variable-rate accounts, and it is not a substitute for the terms your bank publishes. For anything you are committing real money to, confirm the figures with the provider before you decide.
Sources & further reading
Frequently asked questions
Simple vs compound interest — what changes when you deposit monthly?
With simple interest every deposit earns the same flat rate until maturity, so this savings calculator just adds up each month's interest. With monthly compound interest, the interest you have already earned itself earns interest, so later months grow faster. On a monthly deposit plan the gap stays small for short terms and widens over years — this compound interest calculator shows both side by side so you can see the exact difference.
Why does after-tax interest differ from country to country?
Most countries tax the interest your savings earn, and the rate varies. In Korea, for example, savings interest is taxed at 15.4% (14% income tax plus a 1.4% local surtax), while other countries use different rates or tax-free allowances. Because rates differ, this savings calculator lets you type any tax rate — use 0% for a tax-free account or the 15.4% preset for a Korean deposit — and shows the tax withheld and the net interest you actually keep.
Why might my bank statement differ slightly from this calculator?
This recurring deposit calculator assumes deposits on the first of each month, monthly compounding, and whole-number rounding. Real banks may use daily day-count, credit interest on the exact date each deposit lands, apply their own rounding, or pay interest only at maturity. Those small differences can shift the final figure a little, so treat this as a close estimate rather than a to-the-cent quote.
Does this tool assume deposits at the start or end of the month?
It assumes each deposit is made at the start of the month (an annuity-due), so every deposit earns one extra period of interest compared with end-of-month timing. If your real plan deposits at the end of the month you will earn slightly less than shown. Depositing earlier in the cycle is one simple way to squeeze a little more interest out of the same monthly deposit interest calculator plan.
Lump sum vs monthly deposits at the same rate — which earns more?
A single lump sum left for the whole term earns more interest than the same total split into monthly deposits, because the lump sum is invested for longer. In this savings calculator you can model a lump sum by putting it in the starting balance, a savings plan by using the monthly deposit, or combine both to compare them on one screen.