Visualize Your Savings Compounding
See how a starting balance and recurring contributions can grow with compound interest. Toggle compounding frequency, contribution timing (end vs. beginning of period), yearly step-ups, and inflation to view both nominal and inflation-adjusted outcomes.
Outputs include total contributions, earnings, nominal future value, and real (inflation-adjusted) value.
What this calculator assumes
- Compounding frequency applies to interest accrual.
- Contribution timing: end of period (ordinary) or beginning (annuity-due).
- Step-up raises the recurring contribution once per year.
- Real value uses an inflation deflator over the full horizon.
Educational tool—real-world results vary with returns, fees, taxes, and behavior.
Inputs
Results
Includes growth on starting balance and contributions.
Deflated by cumulative inflation over the horizon.
For beginning-of-period contributions (annuity-due), contributions are applied before growth each period; for ordinary annuity, after growth. Yearly step-ups apply at the start of each new year.
How the math works (high level)
A single starting balance grows by compound interest (FV = PV × (1 + r/m)^(m×t)), and periodic contributions are modeled as an ordinary annuity (end-of-period) or annuity-due (beginning-of-period). For annuity-due, values are the ordinary-annuity result multiplied by (1 + r/m).
Real value is approximated by deflating nominal value using inflation over the horizon: real ≈ nominal / (1 + π)^t.
References: compound interest & future value, annuity/annuity-due, nominal vs. real rates (see sources below).
Tips
- Use “beginning of period” timing to model contributions made right after payday.
- Test annual step-ups to reflect raises or planned savings increases.
- Compare nominal vs. real to see purchasing-power impact.
- Try monthly vs. quarterly compounding to learn how frequency affects growth.