Finance

Investment Future Value Monthly Savings Calculator (15 Years)

Estimate the future value of regular monthly savings. This investment version uses a 15-year planning term as its starting point.

What this means: the Future value is the total amount built up from the regular monthly deposits plus the growth earned on them over the full 15-year term, so a larger monthly deposit, a higher rate, or a longer term will raise this final amount.

Formula

Future value uses the monthly rate and the number of monthly deposits to grow each deposit with interest.

How it works

Each monthly deposit earns interest from the month it is made until the end of the term.

Worked example

Monthly deposit $500, annual rate 6%, term 15 years. The monthly rate is 6% divided by 12, which is 0.5% a month, and the number of deposits is 15 times 12, which is 180 months. Using the page formula, the future value is $500 times one plus 0.005 to the power of 180, minus one, divided by 0.005, which gives $145,409.36. That is the calculator's own output for these defaults.

The deposits actually paid in total $90,000, so interest is $145,409.36 minus $90,000, which is $55,409.36. That interest is only an estimate: the 6% rate is the entered assumption, and a lower real average return would leave the same deposit short of this figure.

Who this term suits for an investor: an investor building a substantial portfolio over about 15 years, such as a retirement top-up, a children's education fund invested in the market, or a long-term growth portfolio, where the deposit stays affordable but the final figure is already dominated by growth.

FAQs

How does monthly saving grow?
Regular deposits grow because each deposit earns interest, and that interest then earns more interest.

Is this investment calculator exact?
No, it is an estimate for planning only, based on the numbers you enter.

Are these figures financial advice?
No, they are estimates for planning only, not financial advice. Check with a qualified adviser for decisions involving large sums.

Why does $500 a month reach $145,409.36 in 15 years?
Because 180 deposits of $500 total $90,000, and the remaining $55,409.36 is interest earned on deposits that have had up to 15 years to compound; the monthly rate of 0.5% looks small, but applied to a growing balance for 180 months it adds more than half the deposits again.

Is a 15-year investment plan too long to trust one rate?
Yes, if it is never reviewed, because no fund earns exactly 6% every year for 15 years; the figure is useful as a planning target, but an investor should recheck the plan each year against the actual return and raise or lower the deposit when the return drifts.

What happens if I skip deposits when markets fall?
Skipping deposits during a fall usually hurts more than the fall itself, because the skipped $500 misses the recovery that follows; a 15-year investor who keeps depositing through downturns buys more units cheaply, which is why the habit matters more than timing.

Estimates only, not financial advice. Figures are approximate and do not include all fees, taxes, or changing rates unless stated.