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Future Value Calculator

Future Value Calculator
Interest

Cash Flow: annuity, optional
Answer:

Future Value (FV) of the Lump Sum

$ 25,327.86

Total Interest
$10,327.86


Calculator Use

The future value formula is FV=PV(1+i)n, where the present value PV increases for each period into the future by a factor of 1 + i.

The future value calculator uses multiple variables in the FV calculation:

  • The present value sum
  • Number of time periods, typically years
  • Interest rate
  • Compounding frequency
  • Cash flow payments
  • Growing annuities and perpetuities

The future value of a sum of money is the value of the current sum at a future date.

You can use this future value calculator to determine how much your investment will be worth at some point in the future due to accumulated interest and potential cash flows.

You can enter 0 for any variable you'd like to exclude when using this calculator. Our other future value calculators provide options for more specific future value calculations.

What's in the Future Value Calculation

The future value calculator uses the following variables to find the future value FV of a present sum plus interest and cash flow payments:

Present Value PV
Present value of a sum of money
Number of time periods t
• Time periods is typically a number of years
• Be sure all your inputs use the same time period unit (years, months, etc.)
Interest Rate R
The nominal interest rate or stated rate, as a percentage
Compounding m
• The number of times compounding occurs per period
• Enter 1 for annual compounding which is once per year
• Enter 4 for quarterly compounding
• Enter 12 for monthly compounding
• Enter 365 for daily compounding
• Enter c or continuous for continuous compounding
Cash flow annuity payment amount PMT
The payment amount each period. Use positive values for deposits and negative values for withdrawls.
Growth Rate (G)
If this is a growing annuity, enter the growth rate per period of payments in percentage here. Each payment will increase by this percentage over the previous payment. For example, to increase each annual payment by the rate of inflation then enter the inflation rate here.
Number of payments q per period
• Payment frequency
• Enter 1 for annual payments which is once per year
• Enter 4 for quarterly payments
• Enter 12 for monthly payments
• Enter 365 for daily payments
When do annuity payments occur T
• Select end which is an ordinary annuity with payments received at the end of the period
• Select beginning when payments are due at the beginning of the period
Future Value FV
The result of the FV calculation is the future value of any present value sum plus interest and future cash flows or annuity payments

The sections below show how to mathematically derive future value formulas. For a list of the formulas presented here see our Future Value Formulas page.

Future Value Formula Derivation

The future value (FV) of a present value (PV) sum that accumulates interest at rate i over a single period of time is the present value plus the interest earned on that sum. The mathematical equation used in the future value calculator is

\[ FV=PV+PVi \]

or

\[ FV=PV(1+i) \]

For each period into the future the accumulated value increases by an additional factor (1 + i). Therefore, the future value accumulated over, say 3 periods, is given by

\begin{align} FV_{3}&=PV_{3}(1+i)(1+i)(1+i) \\[0.5em] &=PV_{3}(1+i)^{3} \end{align}

or generally

\[ FV_{n}=PV_{n}(1+i)^{n} \]
Equation 1a

and likewise we can solve for PV to get

\[ PV_{n}=\dfrac{FV_{n}}{(1+i)^n} \]
Equation 1b

The equations we have are (1a) the future value of a present sum and (1b) the present value of a future sum at a periodic interest rate i where n is the number of periods in the future. Commonly this equation is applied with periods as years but it is less restrictive to think in the broader terms of periods. Dropping the subscripts from (1b) we have:

Future Value of a Present Sum

\[ FV=PV(1+i)^{n} \]
Equation 1

Future Value Annuity Formula Derivation

An annuity is a sum of money paid periodically, (at regular intervals). Let's assume we have a series of equal present values that we will call payments (PMT) and are paid once each period for n periods at a constant interest rate i.  The future value calculator will calculate FV of the series of payments 1 through n using formula (1) to add up the individual future values.

\begin{align} FV&=PMT \\[0.5em] &+PMT(1+i)^1 \\[0.5em] &+PMT(1+i)^2+... \\[0.5em] &+PMT(1+i)^{n-1} \end{align}
Equation 2a

In formula (2a), payments are made at the end of the periods.  The first term on the right side of the equation, PMT, is the last payment of the series made at the end of the last period which is at the same time as the future value.  Therefore, there is no interest applied to this payment. The last term on the right side of the equation, PMT(1+i)n-1, is the first payment of the series made at the end of the first period which is only n-1 periods away from the time of our future value.

multiply both sides of this equation by (1 + i) to get

\begin{align} FV(1+i)&=PMT(1+i)^1 \\[0.5em] &+PMT(1+i)^2 \\[0.5em] &+PMT(1+i)^3+... \\[0.5em] &+PMT(1+i)^{n} \end{align}
Equation 2b

subtracting equation (2a) from (2b) most terms cancel and we are left with

\[ FV(1+i)-FV=PMT(1+i)^n-PMT \]

pulling out like terms on both sides

\[ FV((1+i)-1)=PMT((1+i)^n-1) \]

cancelling 1's on the left then dividing through by i, the future value of an ordinary annuity, payments made at the end of each period, is

\[ FV=\dfrac{PMT}{i}((1+i)^n-1) \]
Equation 2c

For an annuity due, payments made at the beginning of each period instead of the end, therefore payments are now 1 period further from the FV.  We need to increase the formula by 1 period of interest growth. This could be written as

\[ FV_{n}=PV_{n}(1+i)^{(n+1)} \]

but factoring out the (1 + i)

\[ FV_{n}=PV_{n}(1+i)^{n}(1+i) \]

So, multiplying each payment in equation (2a), or the right side of equation (2c), by the factor (1 + i) will give us the equation of FV for an annuity due.  This can be written more generally as

Future Value of an Annuity

\[ FV=\dfrac{PMT}{i}((1+i)^n-1)(1+iT) \]
Equation 2

where T represents the type. (similar to Excel formulas) If payments are at the end of the period it is an ordinary annuity and we set T = 0.  If payments are at the beginning of the period it is an annuity due and we set T = 1.

Future Value of an Ordinary Annuity

if T = 0, payments are at the end of each period and we have the formula for future value of an ordinary annuity

\[ FV=\dfrac{PMT}{i}((1+i)^n-1) \]
Equation 2.1

Future Value of an Annuity Due

if T = 1, payments are at the beginning of each period and we have the formula for future value of an annuity due

\[ FV=\dfrac{PMT}{i}((1+i)^n-1)(1+i) \]
Equation 2.2

Future Value Growing Annuity Formula Derivation

You can also calculate a growing annuity with this future value calculator. In a growing annuity, each resulting future value, after the first, increases by a factor (1 + g) where g is the constant rate of growth.  Modifying equation (2a) to include growth we get

\begin{align} FV&=PMT(1+g)^{n-1} \\[0.5em] &+PMT(1+i)^1(1+g)^{n-2} \\[0.5em] &+PMT(1+i)^2(1+g)^{n-3}+... \\[0.5em] &+PMT(1+i)^{n-1}(1+g)^{n-n} \end{align}
Equation 3a

In formula (3a), payments are made at the end of the periods.  The first term on the right side of the equation, PMT(1+g)n-1, was the last payment of the series made at the end of the last period which is at the same time as the future value.  When we multiply through by (1 + g) this period has the growth increase applied (n - 1) times. The last term on the right side of the equation, PMT(1+i)n-1(1+g)n-n, is the first payment of the series made at the end of the first period and growth is not applied to the first PMT or (n-n) times.

Multiply FV by (1+i)/(1+g) to get

\begin{align} FV&\dfrac{(1+i)}{(1+g)} \\[0.5em] &=PMT(1+i)^1(1+g)^{n-2} \\[0.5em] &+PMT(1+i)^2(1+g)^{n-3} \\[0.5em] &+PMT(1+i)^3(1+g)^{n-4}+... \\[0.5em] &+PMT(1+i)^{n}(1+g)^{n-n-1} \end{align}
Equation 3b

subtracting equation (3a) from (3b) most terms cancel and we are left with

\begin{align} FV&\dfrac{(1+i)}{(1+g)}-FV \\[0.5em] &=PMT(1+i)^{n}(1+g)^{n-n-1} \\[0.5em] &-PMT(1+g)^{n-1} \end{align}

with some algebraic manipulation, multiplying both sides by (1 + g) we have

\begin{align} FV&(1+i)-FV(1+g) \\[0.5em] &=PMT(1+i)^{n}-PMT(1+g)^{n} \end{align}

pulling like terms out on both sides

\begin{align} FV&(1+i-1-g) \\[0.5em] &=PMT((1+i)^{n}-(1+g)^{n}) \end{align}

cancelling the 1's on the left then dividing through by (i-g) we finally get

Future Value of a Growing Annuity (g ≠ i)

\[ FV=\dfrac{PMT}{(i-g)}((1+i)^{n}-(1+g)^{n}) \]

Similar to equation (2), to account for whether we have a growing annuity due or growing ordinary annuity we multiply by the factor (1 + iT)

\[ FV=\dfrac{PMT}{(i-g)}((1+i)^{n}-(1+g)^{n})(1+iT) \]
Equation 3

Future Value of a Growing Annuity (g = i)

If g = i we can replace g with i and you'll notice that if we replace (1 + g) terms in equation (3a) with (1 + i) we get

\begin{align} FV&=PMT(1+i)^{n-1} \\[0.5em] &+PMT(1+i)^1(1+i)^{n-2} \\[0.5em] &+PMT(1+i)^2(1+i)^{n-3}+... \\[0.5em] &+PMT(1+i)^{n-1}(1+i)^{n-n} \end{align}

combining terms we have

\begin{align} FV&=PMT(1+i)^{n-1} \\[0.5em] &+PMT(1+i)^{n-1} \\[0.5em] &+PMT(1+i)^{n-1}+... \\[0.5em] &+PMT(1+i)^{n-1} \end{align}

since we now have n instances of PMT(1+i)n-1 we can reduce the equation. Also accounting for an annuity due or ordinary annuity, multiply by (1 + iT), and we get

\[ FV=PMTn(1+i)^{n-1}(1+iT) \]
Equation 4

Future Value of a Perpetuity or Growing Perpetuity (t → ∞)

For g < i, for a perpetuity, perpetual annuity, or growing perpetuity, the number of periods t goes to infinity therefore n goes to infinity and, logically, the future value in equations (2), (3) and (4) go to infinity so no equations are provided.  The future value of any perpetuity goes to infinity.

Future Value Formula for Combined Future Value Sum and Cash Flow (Annuity):

We can combine equations (1) and (2) to have a future value formula that includes both a future value lump sum and an annuity. This equation is comparable to the underlying time value of money equations in Excel.

Future Value

\begin{align} FV&=PV(1+i)^{n} \\[0.5em] &+\dfrac{PMT}{i}((1+i)^n-1) \\[0.5em] &\times(1+iT) \end{align}
Equation 5

As in formula (2.1) if T = 0, payments at the end of each period, we have the formula for future value with an ordinary annuity

\begin{align} FV&=PV(1+i)^{n} \\[0.5em] &+\dfrac{PMT}{i}((1+i)^n-1) \end{align}

As in formula (2.2) if T = 1, payments at the beginning of each period, we have the formula for future value with an annuity due

\begin{align} FV&=PV(1+i)^{n} \\[0.5em] &+\dfrac{PMT}{i}((1+i)^n-1) \\[0.5em] &\times(1+i) \end{align}

Future Value when i = 0

In the case where i = 0, g must also be 0, and we look back at equations (1) and (2a) to see that the combined future value formula can reduce to

\[ FV=PV+PMTn(1+iT) \]

Future Value with Growing Annuity (g < i)

rewritten from formula (3)

\begin{align} FV&=PV(1+i)^{n} \\[0.5em] &+\dfrac{PMT}{(i-g)}((1+i)^{n}-(1+g)^{n}) \\[0.5em] &\times(1+iT) \end{align}
Equation 6

Future Value with Growing Annuity (g = i)

rewritten from formula (4)

\begin{align} FV&=PV(1+i)^{n} \\[0.5em] &+PMTn(1+i)^{n-1} \\[0.5em] &\times(1+iT) \end{align}
Equation 7

Note on Compounding m, Time t, and Rate r

Formula (5) can be expanded to account for compounding.

\begin{align} FV&=PV(1+\frac{r}{m})^{mt} \\[0.5em] &+\dfrac{PMT}{\frac{r}{m}}((1+\frac{r}{m})^{mt}-1) \\[0.5em] &\times(1+(\frac{r}{m})T) \end{align}
Equation 8

where n = mt and i = r/m.  t is the number of periods, m is the compounding intervals per period and r is rate per period t. (this is easily understood when applied with t in years, r the nominal rate per year and m the compounding intervals per year) When written in terms of i and n, i is the rate per compounding interval and n is the total compounding intervals although this can still be stated as "i is the rate per period and n is the number of periods" where period = compounding interval. "Period" is a broad term.

Related to the calculator inputs, r = R/100 and g = G/100. If compounding and payment frequencies do not coincide in these calculations, r and g are converted to an equivalent rate to coincide with payments then n and i are recalculated in terms of payment frequency, q. The first part of the equation is the future value of a present sum and the second part is the future value of an annuity.

Future Value with Perpetuity or Growing Perpetuity (t → ∞ and n = mt → ∞)

For a perpetuity, perpetual annuity, the number of periods t goes to infinity therefore n goes to infinity and, logically, the future value in equation (5) goes to infinity so no equations are provided.  The future value of any perpetuity goes to infinity.

Continuous Compounding (m → ∞)

Calculating future value with continuous compounding, again looking at formula (8) for present value where m is the compounding per period t, t is the number of periods and r is the compounded rate with i = r/m and n = mt.

\begin{align} FV&=PV(1+\frac{r}{m})^{mt} \\[0.5em] &+\dfrac{PMT}{\frac{r}{m}}((1+\frac{r}{m})^{mt}-1) \\[0.5em] &\times(1+(\frac{r}{m})T) \end{align}
Equation 8

The effective rate is ieff = ( 1 + ( r / m ) )m - 1 for a rate r compounded m times per period.  It can be proven mathematically that as m → ∞, the effective rate of r with continuous compounding reaches the upper limit equal to er - 1. [ieff = er - 1 as m → ∞]  Removing the m and changing r to the effective rate of r, er - 1:

formula (5) or (8) becomes

\begin{align} FV&=PV(1+e^r-1)^{t} \\[0.5em] &+\dfrac{PMT}{e^r-1}((1+e^r-1)^{t}-1) \\[0.5em] &\times(1+(e^r-1)T) \end{align}

cancelling out 1's where possible we get the final formula for future value with continuous compounding

Future Value with Continuous Compounding (m → ∞)

\begin{align} FV&=PVe^{rt}+\dfrac{PMT}{e^r-1}(e^{rt}-1) \\[0.5em] &\times(1+(e^r-1)T) \end{align}
Equation 9

for an ordinary annuity

\[ FV=PVe^{rt}+\dfrac{PMT}{e^r-1}(e^{rt}-1) \]
Equation 9.1

for an annuity due

\[ FV=PVe^{rt}+\dfrac{PMT}{e^r-1}(e^{rt}-1)e^r \]
Equation 9.2

Future Value of a Growing Annuity (g ≠ i) and Continuous Compounding (m → ∞)

We can modify equation (3a) for continuous compounding, replacing i's with er - 1 and we get:

\begin{align} FV&=PMT(1+g)^{n-1} \\[0.5em] &+PMT(1+e^{r}-1)^1(1+g)^{n-2} \\[0.5em] &+PMT(1+e^{r}-1)^2(1+g)^{n-3}+... \\[0.5em] &+PMT(1+e^{r}-1)^{n-1}(1+g)^{n-n} \end{align}

which reduces to

\begin{align} FV&=PMT(1+g)^{n-1} \\[0.5em] &+PMTe^{r}(1+g)^{n-2} \\[0.5em] &+PMTe^{2r}(1+g)^{n-3} \\[0.5em] &+PMTe^{3r}(1+g)^{n-4}+... \\[0.5em] &+PMT(e^{(n-1)r})(1+g)^{n-n} \end{align}
Equation 10a

Multiplying (10a) by er/(1+g)

\begin{align} \dfrac{FVe^{r}}{1+g}&=PMTe^{r}(1+g)^{n-2} \\[0.5em] &+PMTe^{2r}(1+g)^{n-3} \\[0.5em] &+PMTe^{3r}(1+g)^{n-4} \\[0.5em] &+PMTe^{4r}(1+g)^{n-5}+... \\[0.5em] &+PMT(e^{nr})(1+g)^{n-n-1} \end{align}
Equation 10b

subtracting (10a) from (10b) most terms cancel out leaving

\begin{align} \dfrac{FVe^{r}}{1+g}&-FV \\[0.5em] &=PMT(e^{nr})(1+g)^{n-n-1} \\[0.5em] &-PMT(1+g)^{n-1} \end{align}

multiplying through by (1+g)

\begin{align} FVe^{r}&-FV(1+g) \\[0.5em] &=PMTe^{nr} \\[0.5em] &-PMT(1+g)^{n} \end{align}

factoring out like terms on both sides then solving for FV by dividing both sides by (er - (1 + g)) we have

\[ FV=\dfrac{PMT}{e^{r}-(1+g)}(e^{nr}-(1+g)^{n}) \]

Adding on the term to account for whether we have a growing annuity due or growing ordinary annuity we multiply by the factor (1 + (er-1)T)

\begin{align} FV&=\dfrac{PMT}{e^{r}-(1+g)} \\[0.5em] &\times(e^{nr}-(1+g)^{n}) \\[0.5em] &\times(1+(e^{r}-1)T) \end{align}
Equation 10

Future Value of a Growing Annuity (g = i) and Continuous Compounding (m → ∞)

Starting with equation (4) replacing i's with er - 1 and simplifying we get:

\[ FV=PMTne^{r(n-1)}(1+(e^{r}-1)T) \]
Equation 11

Example Future Value Calculations:

An example you can use in the future value calculator. You have $15,000 savings and will start to save $100 per month in an account that yields 1.5% per year compounded monthly. You will make your deposits at the end of each month. You want to know the value of your investment in 10 years or, the future value of your savings account.

  • 1 Period = 1 Year
  • Present Value Investment PV = 15,000
  • Number of Periods t = 10 (years)
  • Rate per period R = 1.5% (r = 0.015)
  • Compounding 12 times per period (monthly) m = 12
  • Growth Rate per Period G = 0
  • Payment Amount PMT = 100.00
  • Payments per Period q = 12 (monthly)

Using equation (8) we have

\begin{align} FV&=PV(1+\frac{r}{m})^{mt} \\[0.5em] &+\dfrac{PMT}{\frac{r}{m}}((1+\frac{r}{m})^{mt}-1) \\[0.5em] &\times(1+(\frac{r}{m})T) \end{align}

 

\begin{align} FV&=15,000(1+0.015/12)^{12*10} \\[0.5em] &+\dfrac{100}{0.015/12}((1+0.015/12)^{12*10}-1) \\[0.5em] &\times(1+(0.015/12)*0) \end{align}

 

\begin{align} FV&=15,000(1.00125)^{120} \\[0.5em] &+\dfrac{100}{0.00125}((1.00125)^{120}-1) \\[0.5em] &\times 1 \end{align}

 

\begin{align} FV&=15,000(1.16173) \\[0.5em] &+80,000(1.16173-1) \\[0.5em] &\times 1 \end{align}

 

\begin{align} FV&=17,425.88 \\[0.5em] &+92,938.03-80,000 \\[0.5em] &=$30,361.91 \end{align}

 

At the end of 10 years your savings account will be worth $30,363.91

Try this: Suppose you find a bank that offers you daily compounding (365 times per year). How do the values change?

 

Cite this content, page or calculator as:

Furey, Edward "Future Value Calculator" at https://www.calculatorsoup.com/calculators/financial/future-value-calculator.php from CalculatorSoup, https://www.calculatorsoup.com - Online Calculators

Last updated: March 26, 2024

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