NexaCalc

Finance Calculator

Compound Interest Calculator

Calculate compound growth from a starting amount, recurring contributions, compounding frequency, optional continuous mode, fees and inflation.

Last reviewed: June 22, 2026Finance growth method set v1.0.0: compound growth, cash-flow schedules, APY/APR, CAGR, ROI, FV and PV formulasLocal calculations

Calculator

Compound Interest Calculator

Local finance math

Changing currency changes formatting only. It does not convert values between currencies or fetch exchange rates.

Investment assumptions
amount
amount
years
%
Timing and compounding
Advanced assumptions
%
%
%
%
No result yet. Enter assumptions and calculate to see the result, chart and schedule.
XFacebookLinkedIn

What the Compound Interest Calculator does

Compound Interest Calculator turns entered assumptions into deterministic finance math. It focuses on formula-driven compound growth and contribution timing.

How to use the Compound Interest Calculator

Enter the visible assumptions, choose Calculate, then review the result card, chart, detailed rows, CSV export and warnings.

  • Currency changes formatting only.
  • Rates are entered as annual percentages.
  • Results are estimates from the assumptions, not product quotes.

Formula

FV = PV x (1 + r/m)^(m x t). Contributions are modeled period by period when cash-flow timing is included.

Variables

Common variables are PV for present value, FV for future value, r for annual decimal rate, m for periods per year, t for years, i for periodic rate and PMT for recurring payment.

Assumptions

The calculation keeps full internal precision with Decimal.js and rounds only for display. Investment returns, fees and inflation are assumed constant unless entered otherwise.

Step-by-step calculation

NexaCalc validates the inputs, converts annual rates to periodic rates, applies cash flows in a documented order, aggregates yearly rows and reconciles the displayed schedule to the headline result.

Result interpretation

A higher result means the selected assumptions produce a larger mathematical value. It does not mean the investment, deposit or loan is suitable, guaranteed or officially disclosed.

Worked examples

10,000 at 7% compounded monthly for 10 years grows to about 20,096.61 before contributions.

A 250 monthly contribution adds a cash-flow schedule that separates contributions from growth.

Fees and inflation

Fees, front-end loads and exit loads reduce modeled value. Inflation-adjusted value divides the nominal final value by the inflation factor for the entered horizon.

Contribution timing

Beginning-of-period contributions are added before growth for the period. End-of-period contributions are added after growth and fees for the period.

Limitations

The page does not fetch live market data, does not calculate taxes, does not recommend products and does not replace official disclosures or professional advice.

Financial disclaimer

This calculator provides mathematical estimates for education and planning. It does not guarantee investment performance or replace official financial disclosures or professional advice.

Frequently asked questions

What is compound interest?

Compound interest means growth is calculated on the starting amount plus prior accumulated growth.

What is continuous compounding?

Continuous compounding uses FV = PV x e^(r x t), a mathematical limit rather than a typical product schedule.

Is the Compound Interest Calculator a guarantee?

No. It is mathematical scenario analysis based on the values entered. Actual returns, fees and loan disclosures can differ.

Does changing currency convert values?

No. Currency selection changes formatting only and does not use exchange rates.

Are taxes included?

No. This phase intentionally excludes jurisdiction-specific investment taxes and tax deductions.

Can returns be negative?

Yes where relevant. The calculator allows negative return assumptions above -100% and warns for unusually high assumptions.

Why can official documents differ?

Official documents can use product-specific rules, exact dates, fees, disclosures and rounding conventions that a general calculator does not know.

Does NexaCalc save my financial inputs?

No. Calculations run locally in the browser and the app does not create saved portfolios or accounts.

What does the CSV export include?

Projection tools export yearly schedule rows generated by the same calculation used for the result card.

What precision strategy is used?

The shared engine uses Decimal.js internally and rounds values only for display and exports.

References

  • Investor.gov, Compound Interest Calculator, U.S. Securities and Exchange Commission investor education. Source.
  • Investor.gov, Understanding Fees, investor education on costs and fees. Source.
  • Consumer Financial Protection Bureau, interest rate versus APR borrower education. Source.
  • FDIC, Truth in Savings Act / Regulation DD resource family for APY disclosure context. Source.
  • Electronic Code of Federal Regulations, Regulation Z source family for Truth in Lending APR context. Source.
  • SEC, Mutual Fund Fees and Expenses investor bulletin/source family. Source.

Finance Phase 2 reference families reviewed against Investor.gov, SEC, CFPB, FDIC and regulatory source labels on June 22, 2026.

Financial disclaimer

Investment returns, rates, fees, inflation and cash flows can differ from the assumptions entered. Actual investment values may rise or fall, and past performance does not guarantee future results. Loan APR and deposit APY disclosures may follow product-specific and jurisdiction-specific rules. Review official documents and consult qualified professionals before making a financial commitment.