π Discount Rate Calculator
Build a CAPM discount rate, then discount cash.
CAPM discount rate and present value
Estimates for planning only, not financial advice.
The discount rate converts future money into today's money, and CAPM builds it from risk: risk-free rate plus beta times the market risk premium. With a 4.5 percent risk-free rate, a beta of 1.2, and a 10 percent market return, the discount rate is 11.1 percent. At that rate, $50,000 arriving in 10 years is worth $17,451 today. The riskier the cash flow, the heavier the discount.
How to Use This Calculator
Enter the risk-free rate, the asset's beta, and the expected market return to build the CAPM discount rate. Then enter any future amount and its timing to see the present value at that rate. The two outputs work independently: use the rate for valuation models, the present value for one-off decisions.
Enter the risk-free rate, usually the 10-year Treasury yield, currently near 4 to 5 percent.
Enter beta: 1.0 moves with the market, above 1.0 amplifies it, below 1.0 dampens it. Listed stocks publish betas; private assets need an estimated one.
Enter the expected market return, often 8 to 10 percent for US equities, then the future amount and years to discount it.
The CAPM Formula
CAPM says investors demand the risk-free return plus compensation for systematic risk, the risk that cannot be diversified away. Beta measures that exposure. The model is simple enough to be wrong in interesting ways, but it remains the standard starting point for cost of equity, and every DCF begins with a number built roughly like this one.
Worked Example
Risk-free rate 4.5 percent, beta 1.2, market return 10 percent. Market risk premium = 10 - 4.5 = 5.5 percent. Discount rate = 4.5 + 1.2 x 5.5 = 11.1 percent. A $50,000 payment due in 10 years discounts to $50,000 / 1.111^10 = $17,451.37. The 65 percent haircut looks brutal, but it is the honest price of waiting a decade at equity-like risk. Lower the beta to 0.8 and the rate falls to 8.9 percent, lifting the present value to $21,326.
Choosing the Inputs Honestly
| Input | Common choice | Watch out for |
|---|---|---|
| Risk-free rate | 10-year Treasury yield | Using a short bill rate for long horizons |
| Beta | Published equity beta, unlevered/relevered | Stale betas after big business changes |
| Market return | 8 to 10 percent long-run US | Recency bias from bull markets |
Beyond CAPM
Practitioners often adjust the raw CAPM rate: adding a size premium for small companies, a country premium for emerging markets, or a company-specific risk premium for concentrated customer bases. Each adjustment should be named and justified, not smuggled in. An unexplained "plus 2 percent for risk" is where valuation honesty goes to die. Document every premium so the next person can argue with it.
Common Mistakes
Using a nominal rate to discount real cash flows, or vice versa, mismatches the numerator and denominator. Using book-value weights for a WACC built on this cost of equity is another; markets price risk on market values. Feed this rate into our DCF calculator for full valuations, our present value calculator for general discounting, and check growth assumptions with our IRR calculator.
Real vs Nominal: Match the Cash Flows
A nominal discount rate includes inflation; a real rate strips it out, and mixing them with the wrong cash flows is the most common discounting error in practice. The Fisher relationship links them: (1 + nominal) = (1 + real) x (1 + inflation). With 3 percent inflation, an 11.1 percent nominal rate is about a 7.9 percent real rate. Discount nominal cash flows with the nominal rate, or inflation-adjusted cash flows with the real rate; either pairing works, but crossing them double-counts or ignores inflation.
Most business valuations use nominal throughout, since company forecasts are built in nominal dollars and the Treasury yield is nominal. Real rates appear in regulated utilities, litigation damages, and long-horizon pension math, where inflation adjustment is explicit. The practical rule is simple: look at your cash flows first. If they grow with inflation, your rate must include it; if they are stated in today's dollars, it must not.
Taxes add a second matching problem. An after-tax discount rate must discount after-tax cash flows; a pre-tax rate discounts pre-tax flows. WACC is conventionally after-tax because interest is tax-deductible, so the cash flows it discounts must also be after-tax. Get either pairing wrong and the valuation drifts by the tax rate compounded over the horizon, which is not a rounding error.
From Cost of Equity to WACC
The CAPM rate prices equity, but most projects are funded with debt too, so valuers blend the two into the weighted average cost of capital. WACC weights the after-tax cost of debt and the CAPM cost of equity by their market-value proportions: a company 60 percent equity at 11.1 percent and 40 percent debt at 5 percent after tax has a WACC near 8.7 percent. That blended rate, not the raw CAPM number, discounts firm-wide cash flows in a DCF.
The weights must be market values, and the debt cost must be after tax, since interest shields income. Using book weights or pre-tax debt costs are the two classic WACC errors, and each shifts the answer by a point or more. Build the CAPM rate here first, then blend it with debt in our DCF calculator, which applies the finished rate to full cash-flow forecasts.
Estimates for planning only, not financial advice.
Frequently Asked Questions
What is a discount rate?
The rate used to convert future cash flows into present value. It reflects the time value of money plus compensation for risk: riskier cash flows get higher discount rates and lower present values.
How do you calculate a discount rate with CAPM?
Add the risk-free rate to beta times the market risk premium: r = Rf + beta x (Rm - Rf). With Rf 4.5 percent, beta 1.2, and market return 10 percent, the rate is 11.1 percent.
What is beta in the discount rate formula?
Beta measures how much an asset moves with the overall market. A beta of 1.2 means the asset typically moves 20 percent more than the market in either direction, so investors demand a higher return.
What risk-free rate should I use?
The 10-year US Treasury yield is the standard for long-horizon valuations, currently around 4 to 5 percent. Match the bond maturity roughly to your forecast horizon.
What is the market risk premium?
The extra return investors expect from stocks over risk-free bonds, historically about 4 to 6 percent for the US. It is the (Rm - Rf) term in CAPM.
Can the discount rate be negative?
In theory if beta is deeply negative, but that is rare and usually a data artifact. For valuation work, floor the rate at the risk-free rate rather than defending a negative number.
How does the discount rate differ from the interest rate?
An interest rate is the contractual cost of borrowing. A discount rate is the required return for bearing an investment risk, built from market prices rather than a loan contract.
Why do small companies get higher discount rates?
Smaller firms are riskier and less liquid, so investors demand a size premium, often 2 to 5 percent, on top of CAPM. Ignoring it overvalues small private businesses.
Should I use nominal or real discount rates?
Match the cash flows: nominal rate for nominal cash flows, real rate for inflation-adjusted ones. Mixing them is one of the most common valuation errors.
How sensitive is valuation to the discount rate?
Extremely. A one-point change typically moves a DCF value 10 to 20 percent. That is why the rate deserves more research time than any other single input.