Time Value of Money: Future value, Present value, Annuities Formulas and Important Numerical
Introduction to Time Value of Money (TVM)
The Time Value of Money (TVM) is one of the most important concepts in finance.
It states that money available today is worth more than the same amount in the future because it has the potential to earn interest.
Why is money today more valuable?
Because you can invest money now and earn a return and everything else in future is uncertain.
Interest is the reward for waiting or the cost of borrowing money.
Important Terms
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Principal (P): The original amount of money invested or lent.
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Interest Rate (i): The percentage charged or earned per time period (e.g., 6% per year).
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Time (n): Number of periods the money is invested.
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Future Value (FV): Amount an investment grows to in the future.
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Present Value (PV): Current value of a future amount.
Future Value (Compounding)
Future Value tells us how much an investment made today will be worth in the future.
1. Simple Interest
Interest is earned only on the original principal.
2. Compound Interest
Interest is earned on principal + previous interest (the power of compounding).
Formula: Future Value of a Single Amount
Where:
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FV = Future Value
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PV = Present Value
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i = Interest Rate per period
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n = Number of periods
Note: More frequent compounding (monthly/quarterly) results in a higher future value.
Present Value (Discounting)
Present Value is the current worth of a future sum of money.
It answers:
How much should I invest today to receive ₹X in the future?
Formula
Example on Present value of Money
Alpha Company can invest at 16% interest compounded annually, while Beta Company can invest at 16% interest compounded semi-annually.
Both companies need ₹2,00,000 after 4 years. We will calculate how much each must invest today (Present Value).
Solution
1. Alpha Company – Annual Compounding
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Time period (n) = 4 years
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Interest rate (i) = 16% per year
Formula:
PV = Future Value × 1 / (1 + i)ⁿ
Calculation
2. Beta Company – Semi-Annual Compounding
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Compounding frequency = 2 times per year
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Time period (n) = 4 × 2 = 8
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Interest rate per period (i) = 16% ÷ 2 = 8%
Formula:
PV = Future Value × 1 / (1 + i)⁸
Calculation
Conclusion
Beta Company needs to invest less today because its investment grows faster due to more frequent compounding.
Annuities (Series of Equal Payments)
An annuity is a series of equal payments made at regular intervals of time (e.g., rent, insurance, pension).
1. Future Value of an Ordinary Annuity
The value of all future payments plus interest earned.
Where R = periodic payment (rent)
2. Present Value of an Ordinary Annuity
The lump sum needed today to provide equal future payments.
Example: Future Value of an Ordinary Annuity
In the beginning of 2006, the directors of Molloy Corporation decided that the plant facilities must be expanded in a few years.
The company plans to invest ₹50,000 every year, starting on June 30, 2006, into a trust fund that earns 11% interest compounded annually.
Question
How much money will be in the fund on June 30, 2010, after the last deposit has been made?
Solution
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The first deposit is made at the end of the first year, so it is an ordinary annuity
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Number of periods (n) = 5 years
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Interest rate (i) = 11%
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The last deposit (2010) earns no interest because it is deposited on the final day
From the Future Value of Ordinary Annuity Table,
Future Value Factor (at n = 5, i = 11%) = 6.22780
Formula
FV = Rent × Future Value Annuity Factor
Calculation
Conclusion
Molloy Corporation will have ₹3,11,390 in the fund on June 30, 2010.
Finding the Required Annual Deposit
If the company needs exactly ₹3,00,000 on June 30, 2010, how much must it deposit every year?
Formula
Rent = FV / Future Value Annuity Factor
Calculation
Final Answer
The company must deposit ₹48,171 every year to accumulate ₹3,00,000 by June 30, 2010.
Perpetuities
A Perpetuity is an annuity that pays forever (infinite life).
Examples: perpetual bonds, preferred stock dividends.
Formula
Where C = constant annual payment
Growth Calculations & Doubling Money
1. Compound Annual Growth Rate (CAGR)
2. Rule of 72
A shortcut to estimate how long it takes to double money.
3. Rule of 69 (continuous compounding)
Summary of Important Formulas
