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    Time value / Future value

    Future Value Calculator

    What a lump sum plus a monthly contribution grows to, at a chosen rate and compounding frequency. The mirror image of the present value, and the arithmetic behind every savings projection.

    Future value$300,851Contributions$120,000Growth$170,851
    Future value
    $300,851
    in 20 years
    Contributions
    $120,000
    Money in
    Growth
    $170,851
    Money earned
    Effective annual
    7.23%
    After compounding
    Growth by year
    Balance, contributions and growth to date.
    Growth by year
    YearBalanceContributedGrowth
    Y5$49,973$30,000$9,973
    Y10$106,639$60,000$36,639
    Y15$186,971$90,000$86,971
    Y20$300,851$120,000$170,851

    Compounding is back-loaded: the last years add more than the first.

    Inspect the model
    Choose a quick result view, a scaled comparison, or the complete diagnostic set.
    Balance against time
    The curve steepens because growth compounds on growth.
    Balance against time$0$67.4k$134.8k$202.2k$269.6k$337.0kY0Y0Y2Y2Y4Y4Y6Y6Y8Y8Y10Y10Y12Y12Y14Y14Y16Y16Y18Y18Y20Y20$
    Canonical equations
    The exact relationships implemented by this engine.

    FV = PV(1 + r/n)^(nt) · Compounding.

    FV = PMT · ((1+i)^n − 1)/i · Monthly, at the monthly rate i.

    (1 + r/n)^n − 1 · What the nominal rate really pays.

    finance methodology

    A clear path from inputs to results.

    What a lump sum plus a monthly contribution grows to, at a chosen rate and compounding frequency. The mirror image of the present value, and the arithmetic behind every savings projection.

    Step-by-step methodWorked exampleAssumptions explained

    How to use

    1. Set starting amount ($).
    2. Set annual return (%).
    3. Set years.
    4. Set monthly contribution ($).
    5. Read the headline metrics, then check the table for the detail.

    The formula

    FV=PV(1+r/n)(nt)FV = PV(1 + r/n)^(nt)

    Reference: Compound growth with monthly contributions at the monthly-equivalent rate (Broverman, Mathematics of Investment and Credit).

    Worked example

    At the default inputs

    Inputs
    • Starting amount ($): 10000; Annual return (%): 7; Years: 20; Monthly contribution ($): 500; Contribution growth (%/yr): 0
    Calculation path
    1. 1

      Monthly rate → 0.5833% Compound the lump → $300,851

    Result

    Future value: $300,851 · Contributions: $120,000 · Growth: $170,851

    Interpreting the result

    $10,000 plus $500.00 a month at 7.00% grows to $300,851 in 20 years.

    Assumptions & limitations

    • The return is constant every year.
    • Contributions are made at the end of each month.
    • No fees, tax or inflation.

    Frequently asked questions

    Why is the balance higher than contributions plus starting amount?

    Because each year’s growth earns growth in later years — that is compounding.

    Is a constant return realistic?

    No, but it is the only assumption that gives a single number; sequence risk is covered on the retirement pages.

    What does contribution growth do?

    It raises the monthly amount each year, which matters when you plan to save more as income rises.

    Methodology last reviewed 2026-10-22. Results are informational and not financial or engineering advice — see our disclaimer.