What is a series of future payments worth in today's dollars?
Whenever you're offered a stream of future payments — a pension, a structured settlement, a lottery annuity, a lease — somebody has implicitly priced that stream. The present-value-of-an-annuity formula lets you check whether the price is fair, expensive, or a steal. It's the single most useful calculation in personal finance for "lump sum vs payments" decisions.
A dollar received next year is worth less than a dollar today: you lose a year of investment growth, you incur inflation, and you bear credit risk that the future payment might not arrive. Present value rolls all three into a single discount rate and produces one number that summarizes the stream in today's purchasing power. If the lump sum offered exceeds the PV, take the cash. If not, take the annuity.
PVordinary = PMT × [ 1 − (1+r)−n ] / r
PVdue = PVordinary × (1+r)
Anyone offering you less than $90,073 for this stream is winning the trade; anyone offering more than $90,073 is paying you the time premium.
| Scenario | Discount rate |
|---|---|
| Highly-rated pension (PBGC-backed) | 4-5% (long Treasury + small spread) |
| Lottery annuity (state-backed) | Use state's published rate (~4-5%) |
| Commercial fixed annuity | Match issuer credit rating's yield curve |
| Structured settlement (corporate) | Treasury + 100-300 bps credit spread |
| Personal opportunity cost | Your portfolio expected return (5-7%) |
If the payments are fixed in nominal terms (most pensions, fixed annuities), use a nominal discount rate. If payments are inflation-indexed (Social Security, TIPS-backed), use a real discount rate.
PV = PMT × n. The formula collapses to simple addition — no time-value discount.
Not in the basic formula. For decisions that have different tax consequences (pre-tax lump sum vs annuity payments), compute after-tax PV using your marginal rate.
A coupon bond is PV of an annuity (coupons) plus PV of a single sum (face value at maturity). The same formula applies.
An annuity where payments grow at a constant rate g. PV = PMT/(r−g) × [1 − ((1+g)/(1+r))n]. Useful for inflation-indexed pensions.
Only if you raise the discount rate to include a credit spread. PV at the risk-free rate assumes payments are certain to arrive.
Educational only; not investment advice. Reviewed by David Roehrig, ChFC®, on March 2, 2026.