Discounting calculator
Work out the present value of future cash flows, with the discount factor, a year-by-year breakdown, the effect of inflation and the whole method explained.
What is discounting?
Discounting converts a future amount into what it is worth today. It is the reverse of compounding: where compounding pushes money forward in time, discounting pulls it back to the present. The result is the present value, which is what you would need today to reach that future amount over that time at that return.
The future payment is divided by the compounding factor (1 + i)^N. That quotient is the discount factor, and it is never above one. The higher the rate and the more distant the payment, the smaller the factor and the less that future amount is worth today. With several payments the same step is repeated for each and the results are added up.
Why is money worth more today than tomorrow?
Imagine you can choose: €1,000 today, or €1,000 in a year. Almost everyone takes it today, and there are three good reasons why.
The chance to earn. Money you hold today can be invested. If it earns 5%, in a year it becomes €1,050. A thousand euro in a year is therefore worth less than a thousand today, because it earned you nothing in the meantime.
Inflation. Prices rise over time, so the same amount buys less a year from now. Money loses purchasing power simply by existing.
Uncertainty. A promise of future payment may not be kept. The debtor can go under, the contract can be cancelled. Money in hand carries none of that risk.
Together these three make up the discount rate. The greater the opportunity, the inflation or the risk, the higher the rate, and the less a future payment is worth today.
The formula and where it comes from
Discounting is compounding run backwards. Compounding says that today's amount PV grows into FV over t years:
Solving that equation for PV, dividing both sides by (1 + r)^t, gives the formula for discounting:
If discounting happens more often than once a year, the annual rate is split into periods (i = r/n) and the number of periods multiplied (N = n · t). With several payments the same step repeats for each and the results are added:
What each variable means
The most common mistake is in the units: the rate must be a decimal and the periods must match the discounting frequency.
| Symbol | Name | Jednotka |
|---|---|---|
| Present value | € | |
| Future value | € | |
| Annual discount rate | ||
| Periods per year | ||
| Number of years | years | |
| Rate per period | ||
| Total number of periods | ||
| Discount factor |
A worked example
Where discounting is used
Discounting is not an academic exercise: it underpins almost every valuation in finance.
- Valuing investments
- An investment is only worth buying if its price is below the present value of the future income it will produce.
- Pricing bonds
- A bond's price is the present value of all its coupons plus the discounted face value due at the end.
- Valuing companies (DCF)
- The discounted cash flow method estimates a company's value as the present value of its future free cash flows.
- Retirement planning
- How much you need set aside today to cover future retirement spending is a pure discounting problem.
- Actuarial science
- Insurance reserves are the present value of future claims; without discounting they would be overstated.
Common mistakes
Related calculators
- Compound interestThe other direction: how today's amount grows into the future.
- Future valueWhat today's amount will be worth in a few years.
- InflationHow inflation erodes the purchasing power of money over time.
- Investment appraisalDiscounting a project's income and costs into a single number: NPV, IRR and more.
Related terms
Every term used in this calculator has its own encyclopedia entry with a detailed explanation and derivation.
Related topics
Terms that come up in this calculation
- Present value (PV)What a future sum of money is worth today. It answers the question "how much would I have to have now for it to grow into that".
- Future value (FV)What a sum of money held today will be worth in the future once it has earned interest. It answers the question "how much will this grow into".
- Discount factorA number between zero and one that converts a future payment into its value today. It expresses what fraction of its face amount the payment is worth now.
- The time value of moneyThe principle that a euro today is worth more than a euro in a year. Money in hand can be invested, while money in the future has to be waited for and carries risk.
- InflationThe general rise in prices across an economy, which gradually erodes the purchasing power of money: the same sum buys less in a few years than it does today.
Calculators that follow on from this one
- Compound interestWork out how an investment grows under compound interest, including regular contributions, the effect of inflation, and a year-by-year breakdown.
- InflationSee how inflation will affect the value of your money: how much you will need, and what today's amount will really buy.
- Investment appraisalJudge an investment project on NPV, IRR, MIRR, the profitability index and the payback period, with your own cash flows, charts and every step explained.