compound interest vs benchmark

Compound interest vs benchmark: what is your rate actually beating?

“Good returns” without a reference is marketing. With a benchmark, it becomes analysis.

⚠️ Educational simulation with monthly compounding. It does not replace portfolio advice, suitability review or net return calculations with real taxes and fees.

Initial investment

Monthly contribution

Interest rate

% a.m.

Duration

Meses

Annual inflationUsed to estimate the inflation-adjusted purchasing power of the final balance

% a.a.

Benchmark rateFor example: 0.5% p.m. for savings or 0.9% p.m. for a CDI-like reference

% a.m.

Result

Final balance

R$389,685.15

Total investedR$123,000.00

Accumulated returnsR$266,685.15

ROI216.8%

Real valueR$201,358.28

Difference vs benchmark+R$178,382.52

Your strategyR$389,685.15

BenchmarkR$211,302.63

Mathematical simulation with monthly compounding and recurring contributions. It does not include income tax, IOF, administration fees, custody fees or slippage.

Portfolio growth

Year	Invested	Balance	Returns	Real value
1	R$22,200.00	R$24,511.88	R$2,311.88	R$23,456.34
2	R$29,400.00	R$35,230.10	R$5,830.10	R$32,261.26
3	R$36,600.00	R$47,307.66	R$10,707.66	R$41,455.54
4	R$43,800.00	R$60,916.96	R$17,116.96	R$51,082.60
5	R$51,000.00	R$76,252.25	R$25,252.25	R$61,188.70
6	R$58,200.00	R$93,532.45	R$35,332.45	R$71,823.17
7	R$65,400.00	R$113,004.21	R$47,604.21	R$83,038.71
8	R$72,600.00	R$134,945.47	R$62,345.47	R$94,891.65
9	R$79,800.00	R$159,669.43	R$79,869.43	R$107,442.27
10	R$87,000.00	R$187,529.02	R$100,529.02	R$120,755.13
11	R$94,200.00	R$218,921.89	R$124,721.89	R$134,899.39
12	R$101,400.00	R$254,296.17	R$152,896.17	R$149,949.26
13	R$108,600.00	R$294,156.79	R$185,556.79	R$165,984.33
14	R$115,800.00	R$339,072.74	R$223,272.74	R$183,090.08
15	R$123,000.00	R$389,685.15	R$266,685.15	R$201,358.28

Local browser-based simulation. This is not investment advice.

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What the benchmark is doing here

A benchmark helps measure whether the scenario is worth it relative to a simpler, known or lower-risk alternative.
The final money difference is often more intuitive than staring only at small rate differences on paper.

Questions the comparison answers

Does the strategy beat the reference?

Input: Sua taxa vs benchmark de 0,5% a.m.
Expected output: Diferença final em saldo acumulado

Useful for moving the scenario beyond intuition.

Marginal advantage

Input: Taxas próximas em prazo longo
Expected output: Diferença final pode crescer bastante

Great for visualizing cumulative effects.

Full tool FAQ

Does the calculator model monthly contributions with compound growth?

Yes. The tool compounds the balance month by month and adds the recurring contribution every period, which makes it much more useful for real accumulation planning than a simple lump-sum-only model.

What is the benefit of switching between monthly and annual rate input?

Why compare the scenario against a benchmark?

What does real value mean here?

If I choose 18 months, does the new version keep the exact duration?

Does this calculator already deduct investment taxes?

Can I use it for pensions, ETFs or emergency fund projections?

Is a compound-interest simulation a forecast?

Frequently asked questions

Does the benchmark have to be CDI?

No. It can be any reference rate that makes sense for your comparison.

If I beat the benchmark, is the strategy automatically good?

Not automatically. Benchmark helps interpretation, but risk, liquidity, costs and taxation still matter.