# Compound Interest Calculator

> Project savings growth with compound interest and monthly contributions, year by year.

URL: https://uttir.com/compound-interest-calculator
Categories: calculators
Privacy: Projections are computed locally in your browser.

## About

Compound interest is interest on interest: your balance grows, and the growth itself grows. This calculator projects a starting amount plus optional monthly contributions over up to 100 years, with yearly, quarterly, monthly, or daily compounding.

The year-by-year table shows how much of each year’s balance came from contributions versus earned interest — a clear way to see compounding do the heavy lifting over long horizons.

## How to use

1. **Enter the inputs** — Starting amount, annual rate, years, compounding frequency, and monthly contribution.
2. **Read the summary** — Future value, total contributed, and interest earned.
3. **Review the table** — Year-by-year breakdown of contributions, interest, and balance.

## Examples

### A decade of compounding

$10,000 at 7% compounded monthly with $200/month for 20 years.

Input:

```
P=10000, r=7%, y=20, monthly=200
```

Output:

```
≈ $216,000 future value, of which ≈ $158,000 is interest
```

## FAQ

### How accurate is the projection?

It is exact for the assumptions given (fixed rate, end-of-month contributions). Real returns vary year to year, so treat results as a scenario, not a promise.

### What does the compounding frequency change?

More frequent compounding earns slightly more at the same nominal rate. The calculator converts your chosen frequency to an equivalent monthly growth rate.

### Does it account for taxes or inflation?

No. The projection is pre-tax and nominal. For a rough real-value view, subtract expected inflation from the rate.

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For the full HTML page with the live tool, visit https://uttir.com/compound-interest-calculator.
This file is the markdown rendering at https://uttir.com/compound-interest-calculator.md. See https://uttir.com/llms.txt for a site-wide summary.