Finance / HXD Labs
Project how an initial amount and monthly contributions may grow over time.
Fill in the fields to see the result.
Enter the starting amount, monthly contribution, annual rate and term in months. Choose whether each contribution is added at the start or end of the month, then review the annual balance progression. This estimate excludes taxes, fees and actual market fluctuations.
The annual rate is converted to an equivalent monthly rate. Each month, interest applies to the accumulated balance; choose whether each contribution is added at the start or end of the month. The table shows the balance over time, and the inflation-adjusted value uses the annual rate you enter.
With $1,000 initially, $100 added at each month end for 12 months and a 10% annual rate, the estimated nominal balance is $2,354.05 before taxes and fees.
Rates are held constant only for illustration. Taxes, fees, market volatility and investment risk are excluded.
| Term | Simple Interest (10% p.a.) | Compound Interest (10% p.a.) | Compounding difference |
|---|---|---|---|
| 5 years (60 months) | $1,500.00 | $1,610.51 | +$110.51 (+7.4%) |
| 10 years (120 months) | $2,000.00 | $2,593.74 | +$593.74 (+29.7%) |
| 20 years (240 months) | $3,000.00 | $6,727.50 | +$3,727.50 (+124.3%) |
| 30 years (360 months) | $4,000.00 | $17,449.40 | +$13,449.40 (+336.2%) |
In compound interest you do not divide the annual rate by 12. Instead, use (1 + annual_rate)^(1/12) − 1. For example, 10% per year equals about 0.7974% per month.
When contributing at the start of the month, each new deposit earns interest during that same month. End-of-month contributions are added after that month's interest is calculated.
It estimates the future balance in today's purchasing power by discounting the cumulative inflation rate over the investment term.