Recurring Investment Calculator
Choose a contribution schedule and separate initial capital, recurring contributions and investment growth.
Nominal annual return · compounding each period · constant return assumption
Results
Check the inputs, then calculate your ending value and its components.
Understand this calculation
The contribution is the amount added each time, not an annual total. Nominal annual return is divided by contributions per year; contributions and compounding use the same frequency.
See calculation method and assumptions
Formula
Convert rate and horizon to periods
Add principal growth and accumulated contributions
At zero return, simply add contributions
Growth is the balance less all money added
Contributions and compounding use the same frequency: monthly 12, quarterly 4, yearly 1. n must be an integer. G is modeled net investment growth and may be negative.
Variables, rates and periods
- FV
- Ending value
- G
- Net investment growth; a negative value is a loss
- P
- Initial principal
- A
- Contribution per period
- r
- Nominal annual return as a decimal
- m
- Contribution and compounding periods per year
- t
- Investment years
- i
- Periodic return, equal to r / m
- n
- Contribution periods, equal to m × t
- b
- 1 for beginning contributions; 0 for end contributions
Rates, periods and contribution timing
- r is the nominal annual return as a decimal.
- m is contributions and compounding periods per year: 12 monthly, 4 quarterly, 1 yearly.
- Periodic return i = r / m and n = years × m.
- b = 1 for beginning contributions and 0 for end contributions.
- At zero return, ending value is principal plus all contributions.
Model scope
- Assumes constant contributions and return;
- excludes taxes, fees, inflation and market volatility.
- It does not predict actual investment outcomes.
- Inputs and results are calculated in your browser.
Model an initial investment plus monthly, quarterly or yearly contributions, separating money you add from modeled investment growth.
Worked example
- Enter initial principal 100,000 and contribution 5,000; choose monthly and end of period.
- Set a 7% nominal annual return for ten years; the periodic rate is 7% / 12.
- Compare ending value with 700,000 of total money added; the difference is modeled investment growth.
Frequently asked questions
How do beginning and end contributions differ?
A beginning contribution is added before the period's return and grows for one extra period. With a positive return it produces a higher ending value; at zero return both timings match.
Can I use only principal or only contributions?
Yes. Enter 0 for an absent initial investment or contribution. Use one consistent monetary unit; no currency conversion is performed.
Can the investment period be fractional?
Yes, when it spans whole contribution periods. Monthly contributions for 1.5 years span 18 periods; yearly contributions require whole years. The maximum horizon is 100 years.