Invest a lump sum of PKR 500,000 at a 12% annual rate, compounded monthly, and leave it for 10 years. The
monthly rate is 12% divided by 12, which is exactly 1% per month, and there are 120 months in ten years.
Each month the whole balance earns 1%, and that interest is added back so it earns interest the following
month. After 120 months the future value grows to about 1,650,193. Since you only put in 500,000, the
interest earned is roughly 1,150,193, which is more than twice your original principal. Monthly
compounding edges out annual compounding at the same 12% nominal rate because interest starts earning
sooner, and over a decade that small head start accumulates into a meaningful difference.
Item
Amount (PKR)
Principal
Rs 500,000
Annual rate
12%
Compounding
Monthly, 120 periods
Interest earned
Rs 1,150,193
Future value
Rs 1,650,193
How it is calculated
Compound interest means each period earns a return not only on the original principal but also on all the
interest credited before it, so growth speeds up over time. The tool uses the standard formula, future
value equals principal times one plus the rate over the frequency, all raised to the power of the
frequency times the number of years. It first divides the annual rate by the compounding frequency to get
the periodic rate, then raises one plus that rate to the total number of periods, then multiplies by your
principal. Interest earned is simply the future value minus the principal you started with. Higher
frequencies such as monthly or daily produce a slightly larger result than annual compounding at the same
nominal rate, because interest is credited and starts compounding sooner. The longer the horizon, the more
the interest portion dominates the final balance, which is the core lesson of compounding.
Frequently asked questions
How does compounding frequency change my return?
The more often interest is added to the balance, the more you earn, because each new period earns interest on previously credited interest. Monthly compounding beats annual compounding at the same nominal rate, and daily compounding edges out monthly. This calculator lets you compare the effect by switching the frequency.
Do Pakistani banks typically offer compound or simple interest on savings accounts?
Most scheduled banks in Pakistan credit profit on savings accounts monthly or quarterly, which is effectively compound interest because each credited amount is added to the balance before the next calculation. Conventional banks quote an annual percentage rate while Islamic banks quote an expected profit rate, but both compound the credited amounts at the stated frequency. Always check the product disclosure for the exact compounding schedule before comparing offers.
How does the State Bank of Pakistan policy rate affect compound interest returns?
The State Bank of Pakistan sets a benchmark policy rate that influences the rates commercial banks offer on term deposits and savings accounts. When the policy rate rises, banks tend to increase their deposit rates, which raises the nominal rate you can use in this calculator. Because compounding amplifies even small rate differences over long periods, a 1 or 2 percentage point shift in the policy rate can meaningfully change your projected future value over five to ten years.
Should I account for inflation when using this calculator in Pakistan?
Yes. The PKR amounts this calculator produces are nominal, meaning they are not adjusted for purchasing power. Pakistan has historically experienced periods of elevated inflation, so a future value of Rs 1,650,000 in ten years may buy noticeably less than the same amount today. To get a real-terms estimate, subtract the expected average inflation rate from your nominal interest rate and re-run the calculation. That adjusted rate gives a rough picture of how much genuine purchasing power your investment will accumulate.