Investment Calculator

Lump Sum, Contributions, Goal or Mutual Fund: which mode answers your question

Four modes share one engine, and the mode decides which number you are entitled to read. Lump Sum is for a one-time investment. Contributions is for a regular amount plus an optional starting balance — the same structure as an SIP, at monthly, quarterly, or other frequencies. Goal solves for what it takes to hit a target. Mutual Fund shows the drag from an expense ratio. Whichever one you pick, the tool projects how an investment could grow from the figures you enter — a starting amount, regular contributions, an expected return, a time horizon, and assumptions for inflation and fees — and returns the future value, total invested, growth, and inflation-adjusted value. The output is an educational projection, not a forecast or a guarantee.

Then read the projected value alongside the inflation-adjusted (real) value: a large nominal figure decades out buys less than it looks like it does, and real CAGR shows how fast your purchasing power is actually growing rather than the headline nominal rate. If fees or tax apply, check the scenario comparison to see how sensitive the outcome is to those drags before treating any single number as the answer.

No mode pulls live prices for any specific stock, index, or commodity. You supply the assumed annual return — a long-run S&P 500 average, an expected gold appreciation rate, a fund’s historical return — and the projection follows from that assumption, which is why the same four modes cover shares, index funds, and gold without a separate tool for each. Switch the currency to INR, GBP, EUR, CAD, AUD, SGD, or AED and every figure — inputs, results, and the Excel export — displays in it; the math is unchanged. For SIP step-ups and deeper contribution sensitivity, the dedicated regular-investment calculator goes further than this page’s Contributions mode.

Where the closed-form formula stops and the monthly schedule takes over

The projection is built from the standard time-value-of-money formulas below. When inflation, fees, an expense ratio, step-ups, or tax are enabled, the calculator applies the projection step-by-step across a monthly schedule rather than relying on a single closed-form equation.

That switch is the first of four modelling choices you are accepting when you read a number off this page:

• Projections apply a step-by-step monthly schedule when inflation, fees, an expense ratio, step-ups, or tax are enabled, rather than relying on a single closed-form equation.
• Real (inflation-adjusted) value and real CAGR strip out the inflation rate you enter: Real = FV / (1 + π)ⁿ.
• Optional tax is a simplified flat rate applied to the total gain at the end of the horizon.
• Mutual Fund mode deducts an annual expense ratio (and optional exit load) directly from returns.

One term in those formulas is not an assumption at all but an input you own: compounding frequency. Set it to annual, semiannual, quarterly, monthly, daily, or continuous under compounding frequency, and the schedule, future value, and CAGR all reflect the frequency you chose.

The $310,585 that is really $173,400

Suppose you invest a lump sum of $100,000 for 10 years at an expected 12% annual return, with 6% inflation. Figures are rounded; the live calculator shows exact numbers.

Using the Rule of 72, money at 12% roughly doubles every six years (72 ÷ 12), so over 10 years the nominal balance more than triples. But after 6% inflation, the real value is about $173,400 — judge the goal against that figure, not the headline $310,585.

That gap is what the inflation switch buys you everywhere else on the page. With inflation adjustment on, the tool reports the inflation-adjusted (real) value — what the projected balance could buy in today’s money — and the real CAGR beside it. A large future balance buys less after years of rising prices, so the real figure is usually the better gauge of progress against a goal.

$100,000 invested at once, or spread across the ten years

Both columns invest exactly $100,000 and hold for exactly ten years. The lump goes in on day one; the spread version pays in $833.33 a month for 120 months, so on average that money is only invested for half the period.

The cost of waiting is not fixed — it grows with the return assumption, because the sacrificed time is compounding time. At 6% the spread plan keeps 76% of the lump result; at 12% only 60%. All of this holds under a constant return, which is the whole model here — the order-of-returns table further down is where that assumption is taken apart.

What the table does not settle is which one you should do. In steadily rising markets, investing a lump sum early can win because the money starts working sooner; in volatile markets, spreading the same amount across contributions reduces timing risk, and for most people investing out of income, regular contributions are the only shape available anyway. That is general context, not a recommendation.

A 1% expense ratio, priced in dollars

An expense ratio is quoted as a small annual percentage, which is why it is easy to wave through. Priced as a share of the final balance instead, on the same $100,000 growing at a 12% gross return:

One percent a year is not one percent of the outcome. Over thirty years it removes 24% of the balance, because the fee is charged on the growing balance every year and the money it takes never compounds again. The gap between a 0.2% index fund and a 1% active one is $550,350 on this projection — which is the number an active fund has to beat before it is worth choosing.

Mutual Fund mode applies the same arithmetic to your own figures: it deducts the annual percentage the fund charges straight out of returns and reports the drag against a no-fee version alongside a fee-sensitivity table, so the row that matters is the one carrying your fund’s ratio rather than this example’s.

Why return order moves a drip-fed plan but leaves a lump sum untouched

Ten annual returns — −15%, −5%, 0%, +5%, +8%, +10%, +12%, +15%, +20%, +30% — averaging 8%. Every row below uses those same ten numbers. Only the order changes.

Two things fall out of this table. A lump sum is completely indifferent to the order — multiplying the same ten factors in any sequence gives the identical $202,390, so worst-first and best-first return the same number. A contributor is not: the same decade is worth $94,331 more when the bad years come first, because the cheap years are the ones the later contributions buy into.

The second point is the quieter one. A steady 8% every year produces $13,503 more than the volatile path that averages the same 8%, because a lumpy path compounds at its geometric mean (7.30% here), never its arithmetic one. The projection above uses a constant return, so it is quietly assuming the friendlier of these two worlds.

Which is the standing caveat on every figure here. Investment returns are not guaranteed and can be negative; the smooth growth this page draws is a modelling convenience that real markets do not deliver. Actual results vary with market performance, fees, taxes, inflation, and timing, so treat the numbers as an illustration rather than a promise.

Growth phase only: the five questions this projection hands to another tool

This tool estimates the compounding math of growing money. It does not model:

• Country-specific tax rules on gains, dividends, or withdrawals
• Employer match calculations and contribution limits (401(k)/IRA/pension)
• The withdrawal / drawdown phase of retirement
• Portfolio rebalancing across multiple assets
• Highly volatile investments where year-to-year swings dominate the outcome

The withdrawal line is the one that sends most people elsewhere. This page models the accumulation phase — a lump sum or regular contributions building up — and cannot model the drawdown that follows, so for regular withdrawals from a balance the Retirement Withdrawal Calculator is the right tool, not this one. The other four are the same kind of boundary: each needs rules this engine was never given.

Sources and methodology

This calculator applies a compounding model to the assumptions you enter; it does not fetch live prices or returns, so what is sourced below is the model itself and the published series you can check your assumptions against. Returns are not guaranteed. Links open in a new tab.

• Compound Interest Calculator - the compounding model published by the US securities regulator, the same future-value arithmetic this page applies to a lump sum and to regular contributionsU.S. Securities and Exchange Commission (Investor.gov) · verified 2026-09-01
• Investor Bulletin: How Fees and Expenses Affect Your Investment Portfolio - the source for why the fee drag shown here compounds against you rather than costing a flat amountU.S. Securities and Exchange Commission (SEC) · verified 2026-09-01
• Expense ratio - the definition of the annual fund charge that Mutual Fund mode deducts from returns each yearU.S. Securities and Exchange Commission (Investor.gov) · verified 2026-09-01
• Consumer Price Index - the measured inflation series to sanity-check the inflation rate behind the inflation-adjusted (real) value and real CAGRU.S. Bureau of Labor Statistics (BLS) · verified 2026-09-01
• Stocks - the regulator statement that stock returns are not guaranteed and prices can fall, which is why the constant-return projection here is an illustration and not a forecastU.S. Securities and Exchange Commission (Investor.gov) · verified 2026-09-01

Related calculators

More in Investing, or browse all calculators.

Read the guide

For why identical total contributions can grow to very different amounts depending on timing, see SIP vs Lump Sum Investment Calculation: What the Numbers Actually Show.