? What is present value and why does it matter?
Present value (PV) is the current worth of a future sum of money, discounted at a specific rate. It matters because money today is worth more than the same amount in the future due to earning potential and inflation. PV helps you compare future cash flows on an equal footing with today's dollars.
? How do I calculate the present value of a single payment?
Use the formula: PV = FV / (1 + r)^n, where FV is the future value, r is the discount rate (as a decimal), and n is the number of periods. For example, $100,000 in 10 years at 7% = $100,000 / (1.07)^10 = $50,835.
? What is the difference between ordinary annuity and annuity due?
An ordinary annuity has payments at the end of each period, while an annuity due has payments at the beginning. Annuity due has a higher present value because payments are received sooner. The difference becomes more significant with longer timeframes and higher discount rates.
? How does compounding frequency affect present value?
More frequent compounding (monthly vs. annual) increases the effective discount rate, which decreases present value. Continuous compounding uses the formula PV = FV ร e^(-rรn), providing the maximum discounting effect. The difference is most noticeable with higher rates and longer timeframes.
? What discount rate should I use?
Use a rate that reflects the risk and opportunity cost. For risk-free investments, use Treasury rates (4.2-4.8% in 2026). For corporate projects, use 8-15% for established firms, 20-25% for small businesses. Your discount rate should reflect what you could earn on alternative investments of similar risk.
? How does inflation affect present value?
Inflation erodes purchasing power. A 'real' present value adjusts the discount rate for inflation. If your discount rate is 7% and inflation is 2.6%, your real rate is approximately 4.4%. This shows the true purchasing power of future money in today's dollars.
? Why do small changes in discount rate have large impacts on long-term PV?
Present value uses exponential discounting. Over 20+ years, a 1% rate change compounds exponentially. For example, $100,000 in 30 years: at 3% PV = $41,199, at 4% PV = $30,832โa 25% difference from just 1% rate change.
? What is the 'hurdle rate' in business decisions?
The hurdle rate is the minimum acceptable return on an investment. Businesses use PV calculations to compare projectsโrejecting anything with a PV below the initial investment cost. The hurdle rate typically equals the company's cost of capital or weighted average cost of capital (WACC).
? How do I calculate present value for an annuity stream?
For an ordinary annuity: PV = PMT ร [(1 - (1 + r)^(-n)) / r], where PMT is the periodic payment. For annuity due, multiply by (1 + r). This formula accounts for the time value of each payment in the stream.
? What is the opportunity cost of waiting for future money?
Opportunity cost is what you could earn by investing money today instead of waiting. If you can earn 7% annually, $1,000 today is worth $1,144 in two years. Taking $1,100 in two years means you're losing $44 in opportunity cost compared to investing today.