Dated assumptions · transparent formulas
Present Value
Present value is future value in reverse. This guide shows the discounting formula, a worked example you can verify, and how the discount rate changes the answer.
Educational calculator. Inputs stay in your browser. Historical ranges are not forecasts or investment advice.
Inputs
Estimate comparison
| Assumption | Rate | Nominal FV | Real FV |
|---|---|---|---|
| Lower estimate1-year Treasury constant maturity | 4.28% | $7,915.29 | $6,716.21 |
| Middle estimateS&P 500 rolling 30-year total-return median | 10.80% | $9,621.50 | $8,163.95 |
| Higher estimateS&P 500 rolling 30-year total-return 75th percentile | 12.04% | $9,996.02 | $8,481.74 |
Growth curve and yearly schedule
The same projection engine draws each estimate and feeds the collapsible year-by-year detail.
- Lower estimate
- Middle estimate
- Higher estimate
Show year-by-year detail
| Year | Opening | Deposits | Interest | Ending |
|---|---|---|---|---|
| 1 | $1,000.00 | $1,200.00 | $174.73 | $2,374.73 |
| 2 | $2,374.73 | $1,200.00 | $330.77 | $3,905.50 |
| 3 | $3,905.50 | $1,200.00 | $504.53 | $5,610.03 |
| 4 | $5,610.03 | $1,200.00 | $698.01 | $7,508.04 |
| 5 | $7,508.04 | $1,200.00 | $913.45 | $9,621.50 |
Rate assumptions and sources
Lower / Middle / Higher estimates · reviewed 2026-09-12
- Lower estimate
4.28%
- FRED: 1-Year Treasury Constant Maturity Rate (DGS1)
Retrieved 2026-09-12 · observation 2026-09-10
Dated benchmark snapshot.
- Middle estimate
10.80%
- Damodaran historical returns, 1928-2025
Retrieved 2026-09-12
Median of 69 overlapping 30-year S&P 500 total-return windows through 2025.
- Higher estimate
12.04%
- Damodaran historical returns, 1928-2025
Retrieved 2026-09-12
75th percentile of 69 overlapping 30-year S&P 500 total-return windows through 2025.
- Inflation: 3.34%
- FRED: Consumer Price Index for All Urban Consumers (CPIAUCSL)
Compound annual change from August 2016 to August 2026; user input can replace it.
The formula and how it mirrors future value
Present value divides instead of multiplies: PV = FV / (1 + r/m)^(mt), where the future balance is discounted back over mt compounding periods at the periodic rate r/m.
Every future value projection implies a present value. A projection says what money grows into; discounting says what a future amount is worth today. Both use the same rate and the same compounding mechanics in opposite directions.
Worked example: $50,000 arriving eight years out
Discount a $50,000 future balance back eight years at a 6% annual rate: 1.06^8 is about 1.594, so the present value is roughly $31,400. That is the amount which, invested today at 6%, would grow to $50,000.
The discount rate drives the answer. At 4% the same $50,000 is worth about $36,500 today; at 8% only about $27,000. Nobody can hand you a single present value without also naming the rate behind it.
A useful sanity check pairs this page with the rule of 72: a 6% rate doubles money in about 12 years, so eight years of growth should multiply a balance by noticeably less than 2, and $31,400 grows to $50,000 at that pace.
Choosing a rate and common mistakes
The discount rate is an opportunity cost: what the money could otherwise earn in an investment with similar risk and timing. Using a savings-account rate to discount a risky projection undervalues the future amount; using a stock-market rate for guaranteed cash overstates the risk.
Mixing nominal and real values is the other frequent error. A future balance that already reflects inflation belongs with a real discount rate; a nominal balance belongs with a nominal rate. The calculator separates nominal and real projections for exactly this reason.