Worked example: Investment Calculator
Lump sum. This fixed reference example shows one complete scenario; the interactive results above use your current inputs.
View the example inputs
- Starting balance
- 10000 $
- Nominal annual return
- 7 %
- Investment period
- 10 years
- Compounds per year
- 12
- Monthly contribution (month-end)
- 0 $
| Calculated quantity | Example result |
|---|---|
| Future balance | $20,096.61 |
| Total contributed | $10,000.00 |
| Investment growth | $10,096.61 |
Interpreting retirement and benefit calculations
Match the model to the retirement question
Projecting an account balance, calculating a withdrawal and estimating a rule-based benefit are different tasks. A balance projection needs contribution timing and a return assumption. A finite withdrawal model needs a payout horizon. A benefit formula may instead need an earnings record, an eligibility cohort or a plan multiplier.
Use the exact quantity requested. Current wages are not automatically an indexed lifetime-earnings measure, and an account balance alone does not determine every distribution rule. Age thresholds, annual limits and the supported rule year are described on pages that use them.
Separate nominal amounts from spending power
Future dollars and today’s purchasing power are not the same measure. Inflation can increase a future spending target even when a nominal contribution stays fixed. A selected withdrawal rate is a planning assumption rather than a guarantee that savings will last.
Benefit, tax and contribution rules can include cases beyond this calculator. Review the listed exclusions, and compare multiple return, inflation or timing scenarios when those variables are part of the model.
Formula and calculation method
Effective monthly rate=(1+nominal rate/m)^(m/12)−1. Contributions are made at month-end.
Returns are assumed constant; excludes tax, fees and investment risk. Period must contain a whole number of months.
Reference Sources
Frequently asked questions
How does this calculator work?
Effective monthly rate=(1+nominal rate/m)^(m/12)−1. Contributions are made at month-end.
What assumptions should I check?
Returns are assumed constant; excludes tax, fees and investment risk. Period must contain a whole number of months.
Can I save or print this calculation?
Use Copy link with inputs to reproduce the scenario, Download results for a text record, or Print. Where a schedule is shown, its CSV download includes every row.