Compound Interest Calculator
Project maturity with compounding frequency that matches bank FDs and deposits.
Compound interest with frequency options
Compound interest earns returns on both principal and previously credited interest. This calculator lets you pick yearly, half-yearly, quarterly, or monthly compounding so results match bank FD and deposit product sheets in India.
How to use this calculator
Enter the principal you plan to invest or deposit in one shot. Recurring deposits need the RD calculator instead because each instalment compounds for a different period.
Set the annual interest rate from the product brochure. For FDs, use the rate for your tenure and amount slab, not a headline senior-citizen rate unless you qualify.
Choose compounding frequency carefully. Most Indian bank FDs compound quarterly. Some small savings credit yearly. Monthly compounding is more common in some NBFC and debt products. Higher frequency at the same nominal rate produces a slightly higher maturity.
Compare two frequencies side by side before locking money. The gap between annual and quarterly compounding looks small in year one and larger over ten to fifteen years. Use the year-wise table to see how interest earned each year grows as the base expands.
Tax on interest is not deducted here. Bank FDs may cut TDS when interest crosses the threshold. Post-tax return is what you should compare with inflation. Premature withdrawal penalties also reduce effective yield; check the bank schedule before treating maturity as locked-in.
Compound interest formula
A = P × (1 + r/n)^(n×t) P = principal r = annual rate in decimal n = compounds per year (1, 2, 4, or 12) t = years Interest = A − P Example: ₹1 lakh at 8% for 5 years, quarterly (n=4). A ≈ ₹1.49 lakh, interest ≈ ₹48,600. Same rate compounded yearly yields a slightly lower maturity.
Frequently Asked Questions
Compound vs simple interest?
Simple interest applies only to principal. Compound interest also earns on prior interest, so maturity is higher for the same rate and tenure.
Why does frequency matter?
Interest is added to principal more often when frequency rises, so the next period earns on a larger base.
Bank FD compounding?
Most retail FDs in India compound quarterly. Confirm on the bank rate chart for your product.
PPF compounding?
PPF interest is calculated monthly on the lowest balance between the 5th and month-end, then credited yearly. Use the PPF calculator for accurate PPF math.
Effective annual rate?
EAR = (1 + r/n)^n − 1. Quarterly compounding at 8% has a slightly higher EAR than 8% compounded yearly.
Does this include TDS?
No. Banks may deduct TDS on interest above thresholds. Adjust maturity for tax when comparing after-tax returns.
Rule of 72?
Divide 72 by the annual rate for a rough doubling time. At 8%, money doubles in about 9 years with compounding.
When to use the interest calculator instead?
Use the interest calculator to switch quickly between simple and compound modes. Use this page when you need frequency control and a year-wise schedule.
Senior citizen FD rates?
Banks often add 0.25% to 0.50% for seniors. Enter the higher rate you qualify for; this tool does not auto-apply age-based slabs.
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