Calculator inputs
Example data table
| Scenario | Opening Balance | Rate | Term | Compounding | Adjustment | Projected Ending Balance |
|---|---|---|---|---|---|---|
| Loan balance with monthly payments | $25,000 | 12% | 5 years | Monthly | -$300 monthly | $13,610.45 |
| Credit balance with no payments | $8,000 | 19.5% | 3 years | Daily | $0 | $14,352.88 |
| Savings growth with monthly deposits | $10,000 | 6% | 10 years | Monthly | $250 monthly | $52,081.67 |
| Continuous growth with weekly withdrawals | $15,000 | 7.2% | 4 years | Continuous | -$50 weekly | $18,294.13 |
Formula used
Discrete compounding
A = P × (1 + r / n)n × t
A is future balance, P is opening balance, r is annual rate, n is compounding periods each year, and t is time in years.
Continuous compounding
A = P × er × t
This mode assumes growth happens continuously instead of at fixed intervals.
With periodic adjustments
New Balance = Previous Balance × Growth Factor + Adjustment
Use positive adjustments to add funds. Use negative adjustments to model payments, withdrawals, or balance reductions.
Effective annual rate
EAR = (1 + r / n)n - 1
For continuous mode, the calculator uses EAR = er - 1.
How to use this calculator
- Enter the opening balance you want to project.
- Set the annual interest rate and the total term.
- Choose how often interest compounds.
- Add a periodic adjustment if you expect deposits or payments.
- Choose whether the adjustment occurs at the beginning or end of each period.
- Optionally set a target balance, currency symbol, precision, and start date.
- Press the calculate button to see the result above the form.
- Use the CSV and PDF buttons to export the projection.
Frequently asked questions
1. What does this calculator measure?
It projects how a balance changes over time when interest compounds. It also includes optional recurring adjustments, target tracking, exports, and a visual growth chart.
2. Can I use negative adjustments for loan payments?
Yes. Enter a negative periodic adjustment to model payments or withdrawals. The calculator subtracts that amount at each chosen adjustment date.
3. What is the difference between nominal rate and effective annual rate?
The annual rate you enter is the quoted rate. The effective annual rate shows the real yearly impact after compounding frequency is applied.
4. When should I use beginning versus end timing?
Choose beginning timing when the adjustment happens at the start of each period. Choose end timing when it happens after the period finishes.
5. Does continuous compounding work differently?
Yes. Continuous compounding assumes growth happens at every instant. It uses the exponential formula instead of a fixed period formula.
6. Why does the target date sometimes show as not reached?
That means the balance never crossed your target within the selected term. Try changing the rate, term, or adjustment amount to test other paths.
7. Can I export the results?
Yes. The page includes a CSV export for spreadsheet work and a PDF export for reports, sharing, or recordkeeping.
8. Is this suitable for exact lending disclosures?
No. It is a planning tool. Official loan statements may use fees, day-count rules, compounding conventions, and rounding methods that differ.