Savings projection checklist
How to compare compound interest calculators
A projected balance is a scenario, not a promise. Compare the assumptions that actually change its path.
Compounding knot
- Contributions Amount, timing, and frequency match.
- Compounding Growth is applied on the same schedule.
- Two totals Savings stay distinct from projected growth.
Before you compare
Use the same starting balance, contributions, compounding, and time horizon in every tool. Then separate money you add from growth created by the return assumption before deciding what the result means.
Updated:
Enter
Contributions
amount, timing, and frequency
Confirm
Compounding
how and when growth is applied
Read
Both totals
contributions and projected growth
Split the modelled balance
$200/month for 40 years at a stated 7% annual return, compounded monthly, no starting balance, no fees or taxes. Ask every tool to show this split.
Contributions vs modelled growth
Hold the inputs constant
Use the same starting balance, contribution amount, return assumption, investment period, and compounding frequency in each calculator. A comparison is not meaningful when one tool treats contributions as beginning-of-period deposits and another treats them as end-of-period deposits.
Look for the assumptions that change the result
- Whether the stated return is nominal or adjusted for inflation.
- Whether the return is an assumption, a guaranteed rate, or a historical illustration.
- Whether fees, taxes, withdrawals, and irregular contributions are included or excluded.
Separate savings from projected growth
A useful result makes it clear how much of the ending balance comes from contributions and how much comes from the return assumption. That separation helps a reader test a lower return, a longer saving period, or a different contribution amount without treating one projected total as a promise.
Use sensitivity checks
Run at least a conservative, middle, and higher-return scenario. If a small change in the assumed rate or timeline materially changes the outcome, that uncertainty belongs in the decision rather than in a hidden default.
Try the scenario yourself
Use the CalcMesh compound interest calculator to compare assumptions using your own values. For investing concepts and risk disclosures, consult the SEC's Investor.gov education materials.
Limitations
This page is a comparison checklist, not a test, ranking, certification, or endorsement of other calculator providers. Investment returns, fees, taxes, and withdrawals can make a real outcome differ from any projection.