Deep guide · India
Compound interest calculator — frequency, growth, maturity
₹29,00,000, 13% nominal, 22 years, compounded 1 time(s) per year: balance about ₹4,26,70,109, interest about ₹3,97,70,109. Compound interest means each period’s interest is earned on the running total — principal plus interest already credited — unlike simple interest on the original principal alone.
Every time interest posts, the base for the next period grows. Over years, that feedback magnifies small changes in rate, tenure, or compounding frequency.
Later sections unpack the formula, your inputs, sensitivity tables, a frequency grid, and a simple-interest check. These are teaching numbers — not a bank quote, not tax guidance, not a market outlook.
Studying? Read straight through. Shopping deposits? Compare tables here, then read the issuer’s rate sheet, TDS, and terms — or ask a professional.
How compound interest works (nominal rate and periods)
A standard textbook form uses nominal annual rate R (percent), compounding n times per year, and t years: maturity ≈ P × (1 + R/(100n))^(n×t). Your page uses that structure with P = ₹29,00,000, R = 13%, n = 1, t = 22 years.
Simple interest on the same principal would be linear in time on P alone; compounding instead repeatedly applies the period rate to an evolving balance. That is why the “interest” row grows faster than a straight multiple of years when n > 0 and t is long enough for the effect to show up clearly in rupee terms.
Your scenario — line-by-line breakdown
- Principal (P): ₹29,00,000
- Nominal annual rate: 13%
- Time: 22 years
- Compounding frequency: 1 per year
- Total compound interest: ₹3,97,70,109
- Maturity (P + interest): ₹4,26,70,109
For contrast only, simple interest on the same P, R, T would total about ₹1,11,94,000 — roughly ₹3,14,76,109 higher with compounding under these assumptions.
Same P, R, T — different compounding frequencies
Holding principal, annual rate, and tenure constant, increasing compounding frequency typically raises maturity when the nominal annual rate is unchanged — the table shows the pattern for common n values.
| Times/year | Interest | Maturity |
|---|---|---|
| 1 | ₹3,97,70,109 | ₹4,26,70,109 |
| 2 | ₹4,34,21,300 | ₹4,63,21,300 |
| 4 | ₹4,54,86,399 | ₹4,83,86,399 |
| 12 | ₹4,69,65,534 | ₹4,98,65,534 |
Scenario tables — tenure, rate, and principal
Different tenures (same P, R, frequency)
| Years | Interest | Maturity |
|---|---|---|
| 1 | ₹3,77,000 | ₹32,77,000 |
| 2 | ₹8,03,010 | ₹37,03,010 |
| 3 | ₹12,84,401 | ₹41,84,401 |
| 5 | ₹24,43,062 | ₹53,43,062 |
| 7 | ₹39,22,556 | ₹68,22,556 |
| 10 | ₹69,44,245 | ₹98,44,245 |
| 15 | ₹1,52,37,384 | ₹1,81,37,384 |
| 20 | ₹3,05,16,955 | ₹3,34,16,955 |
Different rates (same P, T, frequency)
| Scenario | Rate | Interest | Maturity |
|---|---|---|---|
| -25% vs base | 9.8% | ₹1,97,80,336 | ₹2,26,80,336 |
| -15% vs base | 11% | ₹2,59,07,365 | ₹2,88,07,365 |
| Base rate | 13% | ₹3,97,70,109 | ₹4,26,70,109 |
| 15% vs base | 15% | ₹5,98,69,763 | ₹6,27,69,763 |
| 25% vs base | 16.3% | ₹7,74,80,689 | ₹8,03,80,689 |
Different principals (same R, T, frequency)
| Scenario | Principal | Interest | Maturity |
|---|---|---|---|
| -25% vs base | ₹21,75,000 | ₹2,98,27,582 | ₹3,20,02,582 |
| -15% vs base | ₹24,65,000 | ₹3,38,04,593 | ₹3,62,69,593 |
| Base principal | ₹29,00,000 | ₹3,97,70,109 | ₹4,26,70,109 |
| 15% vs base | ₹33,35,000 | ₹4,57,35,626 | ₹4,90,70,626 |
| 25% vs base | ₹36,25,000 | ₹4,97,12,637 | ₹5,33,37,637 |
Practical notes (deposits, loans, and exams)
Exam problems often test whether you converted years to months correctly, whether the rate is annual or monthly, and whether to report interest only or maturity. When in doubt, write the timeline on paper, apply one period at a time, and reconcile with this calculator’s headline numbers.
Real banks publish effective yields, minimum slabs, and TDS rules that a textbook model does not capture. Treat this page as a structured explanation tied to your inputs — then validate against the actual scheme documentation.
Frequently asked questions
- What is the maturity for ₹29,00,000 at 13% compounded 1 time(s)/year?
- Estimated maturity is ₹4,26,70,109 with interest about ₹3,97,70,109. More compounding periods per year usually lift maturity slightly when the nominal annual rate is unchanged, because interest is credited more often and begins earning its own return.
- What is the compound interest formula (intuition)?
- Each period, interest is calculated on the updated balance (principal plus previously accumulated interest). That feedback loop is why growth accelerates versus simple interest on the original principal alone.
- Compound interest vs simple interest for the same numbers?
- Here, compound growth lands near ₹4,26,70,109 while simple interest on the same principal, rate, and years would total about ₹1,11,94,000 — the wedge is the reinvestment effect.
- Compound interest vs SIP?
- Compound interest describes how a single lump grows. SIP describes how you add money monthly. Mutual fund SIPs combine periodic contributions with market-linked compounding — use both calculators for different questions.
- Does nominal annual rate equal effective annual rate?
- Not always. More frequent compounding increases the effective yield when the quoted annual rate is held constant. Compare scenarios using the frequency table below.
- Where can I explore more scenarios?
- Use internal links for nearby principals, tenures, rates, and frequencies. Cross-check with the simple interest calculator for the same P, R, T to see the contrast.
Internal linking — related compound interest pages
Explore nearby scenarios on EasyCal — each link opens a calculator page with matching inputs (programmatic SEO).
- Compound interest — ₹30,00,000 (30 lakh) · 22 yrs @ 13% (freq 1)
- Compound interest — ₹31,00,000 (31 lakh) · 22 yrs @ 13% (freq 1)
- Compound interest — ₹34,00,000 (34 lakh) · 22 yrs @ 13% (freq 1)
- Compound interest — ₹28,00,000 (28 lakh) · 22 yrs @ 13% (freq 1)
- Compound interest — ₹27,00,000 (27 lakh) · 22 yrs @ 13% (freq 1)
- Compound interest — ₹29,00,000 (29 lakh) · 24 yrs @ 13% (freq 1)
- Compound interest — ₹29,00,000 (29 lakh) · 27 yrs @ 13% (freq 1)
- Compound interest — ₹29,00,000 (29 lakh) · 20 yrs @ 13% (freq 1)
- Compound interest — ₹29,00,000 (29 lakh) · 17 yrs @ 13% (freq 1)
- Compound interest — ₹29,00,000 (29 lakh) · 25 yrs @ 13% (freq 1)
Educational illustration only — not tax or investment advice.