Understanding Present Value: How to Evaluate Investments
Calculate exactly what a future sum of money is worth today using our Present Value Calculator, or read on to understand the concept of discounted cash flows.
If you win the lottery, they often give you a choice: take a $500,000 lump sum today, or receive $1,000,000 paid out over 30 years. Which is the better financial decision?
To answer this, you cannot look at the Future Value. You must look backward and calculate the Present Value (PV). Present Value tells you exactly how much money you would need to invest today at a specific interest rate to equal that future payout.
If the Present Value of the 30-year payout is less than $500,000, you should take the lump sum!
The Concept of "Discounting"
Calculating Future Value requires compounding (growing money forward in time). Calculating Present Value requires discounting (shrinking money backward in time).
When you "discount" a future cash flow, you are removing the interest it would have earned between now and the payout date. The rate at which you shrink the money is called the Discount Rate.
The Discount Rate is highly subjective. It represents your "Opportunity Cost"—the rate of return you believe you could earn if you had the cash in your hand today (e.g., if you believe you can earn 7% in the stock market, your discount rate is 7%).
The Present Value Formula
The Present Value formula is simply the Future Value formula algebraicaly reversed.
PV = FV / (1 + r)^n
Where:
- PV = Present Value (what it's worth today)
- FV = Future Value (the promised future payout)
- r = Discount Rate (your expected rate of return, as a decimal)
- n = Number of periods (years) until payout
Example Calculation
Your wealthy uncle promises to give you $50,000 on your 30th birthday, which is exactly 5 years from today.
You want to know what that promise is actually worth to you right now. You assume that if you had the money today, you could invest it in safe bonds earning 5%.
PV = 50,000 / (1 + 0.05)^5
PV = 50,000 / (1.05)^5
PV = 50,000 / 1.2762
PV = $39,178.81
The promise of $50,000 in five years is mathematically identical to having $39,178 in your bank account today.
Why Present Value Matters in Business
Present Value isn't just for lottery winners or inheritances. It is the core mathematical formula used by Wall Street analysts and corporate executives to evaluate business decisions.
Imagine a company wants to buy a new machine for $100,000. They estimate the machine will generate $120,000 in profit over the next 10 years.
To decide if they should buy it, the CFO will calculate the Present Value of that future $120,000. If the Present Value of the future profits is less than the $100,000 they have to spend today, the machine is a bad investment, and they will reject the purchase.
FAQ
What happens to Present Value if inflation is high? If inflation is high, your "Discount Rate" must increase to account for the lost purchasing power. As the Discount Rate (the denominator in the equation) gets larger, the Present Value drastically shrinks. High inflation destroys the present value of future promises.
Don't accept long-term payouts or annuities without checking the math. Evaluate your financial options instantly using the CalcUnit Present Value Calculator.