Investment Calculator

An ordinary annuity makes contributions at the END of each compounding period, which is the default. An annuity-due makes contributions at the BEGINNING of each period, giving each contribution one extra period to compound. For the same inputs, an annuity-due always produces a slightly higher future value — multiplied by (1 + periodic rate).

Higher compounding frequency means interest is calculated and credited more often, slightly increasing your effective annual return. For example, at 8% annual rate: annual compounding gives an effective rate of 8.00%, monthly compounding gives 8.30%, and daily gives 8.33%. The difference grows more significant over longer time horizons and with larger balances.

Future value is the projected total balance of your investment at the end of the chosen period, assuming the specified rate of return is earned consistently. It includes your initial investment, all contributions made over time, and all interest/returns accumulated through compounding.

Yes. When the annual rate is set to 0%, the calculator special-cases the formula — the standard compound interest formula becomes mathematically undefined at zero rate, so the result is simply the sum of your initial investment plus all contributions made: FV = initial amount + (contribution per period × total periods).

This calculator uses a constant assumed rate of return, while real investment returns fluctuate year to year. It also does not account for fund expense ratios, management fees, taxes on capital gains or dividends, or contribution timing irregularities. The result is a mathematical projection, not a guarantee.

The calculator combines two formulas: (1) Lump-sum growth: FV_lump = PV × (1 + r/m)^(m × t), and (2) Future value of an annuity: FV_annuity = PMT × [((1 + r/m)^(m × t) − 1) / (r/m)]. For contributions at the beginning of each period (annuity-due), the annuity term is multiplied by (1 + r/m). The total future value is FV_lump + FV_annuity.

Rearrange the annuity formula: PMT = (FV − PV × (1 + i)^n) × i / ((1 + i)^n − 1), where i = r/m is the periodic rate and n = m × t is the total periods. Enter your target as future value, adjust the contribution field, and observe when the projected balance meets your goal. A dedicated savings-goal calculator (available on this site) solves for PMT directly.

Not exactly. Compound interest is a specific mechanism — interest earned on previously earned interest. Investment return is a broader term covering price appreciation, dividends, and interest across any asset class. This calculator models compound growth at a constant rate, which approximates bank deposits, bonds, and long-run stock-market averages, but simplifies the variable annual returns of equities.

The formula remains mathematically valid for negative rates — it models a scenario where the investment loses value each period (e.g., a −5% annual loss). The future value will be less than your total contributions, reflecting the combined effect of losses and ongoing deposits. This can be useful for stress-testing a portfolio or modeling inflation erosion in real terms.

The Rule of 72 is a quick mental shortcut: divide 72 by the annual interest rate to estimate the number of years needed to double your money. For example, at 8% per year, money roughly doubles in 72/8 = 9 years. This calculator shows the full growth curve, so you can verify or refine that estimate with exact compounding frequency and regular contributions included.

Starting earlier dramatically increases the final balance because compounding is exponential — each year’s growth is applied to an ever-larger base. For instance, investing $10,000 at 8% monthly for 20 years yields roughly $49,268, while doing it for 30 years yields $109,357 — more than double for 50% more time. Use this calculator to compare start-now vs. wait-a-year scenarios to see the cost of delay concretely.

It can provide a preliminary growth projection, which is a useful starting point. However, retirement planning typically also requires modeling inflation (purchasing-power erosion), tax treatment (pre-tax vs. post-tax accounts), account-specific limits (401k, IRA, PPF), withdrawal-phase drawdown, and Social Security or pension income. For a fuller picture, consult a qualified financial advisor alongside this calculator.

The calculator models any investment that grows at a fixed compound rate — bank fixed deposits, recurring deposits, bonds held to maturity, money-market funds, or a stock-market index fund where you use a long-run assumed average. It does not model variable-rate instruments, dividends paid out rather than reinvested, or assets whose returns are path-dependent (options, real estate cash flows). For those, the projected rate is still a useful planning number; just treat it as a scenario, not a forecast.

The right rate depends on the asset class. Broad stock-market index funds (e.g. S&P 500 or Nifty 50) have delivered roughly 10–12% per year in nominal terms over multi-decade periods, or around 7–8% after inflation. Investment-grade bonds have historically returned 3–5% per year. Bank fixed deposits and savings accounts vary by country and rate cycle — check current advertised rates. For planning purposes, many financial educators suggest using 6–8% for a balanced equity/bond portfolio, which tends to be conservative enough to avoid over-optimism. Whatever rate you choose, run a second scenario 2–3 percentage points lower to stress-test the outcome.