Investor Corner/Start here/Foundations
1.1.2 Time Value of Money
₹1 today is worth more than ₹1 a year from now, because today's rupee can be put to work immediately. This single idea underlies every return calculation, every loan, and every investing decision.
Why a rupee today beats a rupee tomorrow
If you have ₹1 today, you can invest it and it can start earning immediately. A rupee promised to you a year from now cannot start earning until it actually arrives. The difference between the two is the time value of money: the earning potential lost simply by waiting.
This is why lenders charge interest, why a discount for paying early makes economic sense, and why financial planning always asks not just how much but when.
The idea sounds academic but drives everyday decisions. A zero-cost EMI has the time value of money already priced into a higher sticker price or a manufacturer subvention. A retention bonus payable in two years is worth less today than its headline number. Understanding time value is what lets you see through these structures to the actual economic deal underneath.
A simple illustration
₹100 invested today at 10% a year is worth ₹110 in a year, ₹161 in five years, and ₹259 in ten years. Money promised to you in ten years, with no return along the way, is simply ₹100 in ten years' time. That is worth far less in today's terms than ₹100 you could invest right now.
The same logic runs in both directions. Future value asks what ₹X invested today becomes; present value asks what amount today is needed to reach ₹X later. A ₹3 crore retirement goal in twenty-five years has a present value of roughly ₹17.6 lakh at a 12% return, which is the lump sum needed today to reach it with no further contribution. This is also why delaying a SIP by even two or three years costs far more than the missed contributions: the earliest instalments have the longest runway and do the most compounding.
Where this shows up in practice
Every present-value and future-value calculation, every bond price, every EMI, and every retirement projection rests on this idea. It is also the reason two investments with the same headline return can differ enormously depending on when the cash flows actually happen. That timing problem is exactly what XIRR is built to solve for irregular contributions like a SIP.
The single most important input in any such calculation is the discount rate. ₹1 crore twenty years out is worth ₹14.9 lakh today at 10% but only ₹6.1 lakh at 15%, so a five-point change in the assumed rate more than halves the present value. This is why the return assumption in a retirement calculator matters so much: an unrealistically high figure makes the plan look comfortable on paper while setting up a real shortfall. Conservative assumptions are not pessimism; they are the time value of money demanding honest inputs.
How PriLytics helps. Because SIPs, lump sums and withdrawals happen on different dates, a simple average return can be misleading. PriLytics computes XIRR for every holding, which correctly accounts for exactly when each rupee went in or came out. See how returns are calculated.