Used for all ending-value calculations
← All toolsAFTER-FEE RETURN3.00% ESTIMATED FEE DRAG$0 TODAY'S PURCHASING POWER$12,542 LOWER1.0% CURRENT3.0% HIGHER5.0%
PRIVATE, EDUCATIONAL CALCULATOR
Compound interest calculator
Build a long-term scenario with daily, monthly, or annual contributions. Start at 3%, then check fee drag, today's purchasing power, the goal gap, and the required contribution.
PLANNING INPUTSBuild a comparable scenario
QUICK SCENARIOS
ANNUALIZED CONTRIBUTION$1,200Use this to check whether different frequencies are truly comparable
%
Goal and real-world adjustments
Every value is an editable planning assumption; no market, product, or inflation data is fetched automatically.
The fee is a simplified ongoing percentage-of-assets model; transaction costs, tax, and one-off charges are excluded. The 2% inflation default is a placeholder assumption, not a current CPI reading; the default target only demonstrates the goal calculation.ESTIMATED VALUE IN 10 YEARS$15,289
3.0% before fees · 0.00% annual fee · 3.00% modeled return after fees
CONTRIBUTED$13,000
MODELED GROWTH+$2,289
GROWTH SHARE15.0%
GOAL PROGRESS$20,000
76.4%The scenario is $4,711 short. Reaching the target in 10 years requires about $134 per month, or $34 more than the current contribution.
At the current contribution path, the model reaches the nominal target in about 12.8 years.Compared with the same scenario at a 0% annual fee
At 2.0% constant inflation; 0.98% modeled real return
YEARLY PATHEnding value vs. contributed money
Dark green = ending value · Light green = contributedY1
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RETURN SENSITIVITYPre-fee return 2 points lower, current, and 2 points higher
Annual fee stays at 0.00%; all other inputs are unchanged$13,717
1.00% after fees · −$1,572$15,289
3.00% after fees · baseline$17,065
5.00% after fees · +$1,776Raising the pre-fee return from 3.0% to 5.0% adds $1,776 to the modeled ending value. This shows sensitivity, not a recommendation; higher potential returns generally come with greater risk.
MILESTONESCheck the yearly math
Ending value includes the annual fee; purchasing power uses constant inflation| Year | Contributed | Modeled growth | Ending value | Today's purchasing power |
|---|---|---|---|---|
| 1 | $2,200 | +$46 | $2,246 | $2,202 |
| 2 | $3,400 | +$130 | $3,530 | $3,393 |
| 3 | $4,600 | +$253 | $4,853 | $4,573 |
| 4 | $5,800 | +$415 | $6,215 | $5,741 |
| 5 | $7,000 | +$617 | $7,617 | $6,899 |
| 6 | $8,200 | +$862 | $9,062 | $8,047 |
| 7 | $9,400 | +$1,151 | $10,551 | $9,185 |
| 8 | $10,600 | +$1,484 | $12,084 | $10,313 |
| 9 | $11,800 | +$1,862 | $13,662 | $11,432 |
| 10 | $13,000 | +$2,289 | $15,289 | $12,542 |
The model uses an effective annual return, estimates the after-fee rate as (1 + pre-fee return) × (1 − annual fee) − 1, and adds contributions at each selected period-end; daily scenarios use 365 periods per year. Transaction costs, tax, currency movements, withdrawals, and real market volatility are excluded. Your values are not uploaded.
Normalize contribution frequency before comparing results
A daily $100 contribution, a monthly $100 contribution, and an annual $100 contribution are very different cash flows. The annualized contribution makes that difference visible. Each contribution is added at the end of its selected period; daily scenarios use 365 periods and do not separately model leap years.
Why the default return is 3%
The site uses 3% as a restrained base input so the first screen does not begin with an aggressive long-term projection. It is not a deposit rate, market forecast, product recommendation, or guaranteed return. Actual outcomes depend on the asset, fees, tax, currency, horizon, and return path.
How to read the return labels
These bands describe only how aggressive the calculator input is. They do not replace a risk assessment of a specific product. The same 3% assumption can come from assets with very different risks, and a high input does not make that outcome attainable.
| Annual return before fees | Label | How to use it |
|---|---|---|
| Below 0% | Loss stress case | Shows how a drawdown affects the plan; it is not a worst case. |
| 0% to below 2% | Conservative | Nominal growth is limited and purchasing power may still fall after inflation. |
| 2% to 4% | Baseline planning | The 3% default sits here and exists only to create a comparable base case. |
| Above 4% to 7% | Growth-oriented | Depends more on sustained market performance and should be paired with a lower case. |
| Above 7% | High-return | Long-term outcomes are easier to overstate, while potential return and loss risk generally rise. |
Do not focus only on a higher return
The sensitivity cards move the current return two percentage points lower and higher. U.S. securities-regulator education notes that greater potential returns generally come with greater risk and loss potential. Contribution amount, frequency, fees, and time horizon are often more controllable inputs.
Move from an ending value to a goal gap
An ending value alone does not tell someone what to do next. After a target is entered, the tool shows progress, the nominal gap, modeled time to target, and the contribution required at the selected frequency under the current horizon and after-fee return. These reverse calculations still depend on a constant return and are not guarantees.
Put fees and purchasing power beside the headline result
The annual ongoing fee is modeled as a simplified percentage of assets. The calculator shows its estimated drag and converts the nominal ending value into today's purchasing power using the entered constant inflation rate. U.S. securities-regulator education notes that even small ongoing fees can materially reduce a portfolio over time, while inflation reduces purchasing power.
Calculation limits and next checks
The ending value uses one constant effective annual return and ongoing annual fee; today's purchasing power uses constant inflation. The model still does not include return sequence, drawdowns, transaction costs, tax, one-off fees, currency movements, or withdrawals. Next, use the inflation calculator to check future purchasing power, and run at least one lower or negative-return stress case.
Method references: Investor.gov Compound Interest Calculator; risk-and-return guidance: Investor.gov; fee impact: Investor.gov Investor Bulletin; purchasing power: Investor.gov.
This is general educational information, not investment, tax, or financial advice.