Investing calculators
Valuation & corporate
Determine fair value and company quality.
Graham intrinsic value
What it measures
A variation of the Benjamin Graham formula to estimate the intrinsic value of a growth stock. It considers earnings, growth rate, and the current cost of money (bond yields).
When to use it
Use it as a rough valuation anchor. If a stock trades at $100 and the formula puts its value at $50, the price may be hard to justify.
Watch out for
This formula is sensitive to growth assumptions. It was designed for stable companies, not hyper-growth tech stocks.
Read the guide: What is the P/E Ratio? How to Actually Use It
Graham intrinsic value
Estimates fair value from earnings and growth.
Enterprise value (EV)
What it measures
Enterprise value (EV) is the theoretical price of buying the entire company. A buyer pays for all the shares (market cap) and takes on the debt, but also gets the cash on the balance sheet.
When to use it
Use EV rather than market cap when comparing companies with different levels of debt. A company with a low market cap but heavy debt may actually be expensive.
Watch out for
EV can be negative if a company holds more cash than its market cap plus debt. This is rare, but it does happen with distressed tech and biotech companies.
Enterprise value (EV)
The full cost of acquiring a company, including its debt.
WACC
What it measures
Weighted Average Cost of Capital (WACC) is the average rate a company expects to pay to finance its assets. It combines the cost of equity (shareholders) and the cost of debt (lenders).
When to use it
Used as the discount rate in DCF models. If a company's WACC is 8%, a new project must return more than 8% to create value.
Watch out for
Debt is usually cheaper than equity because interest is tax-deductible (the tax shield). Too much debt, however, raises the risk of bankruptcy.
Read the guide: What is WACC? The Discount Rate Explained Simply
WACC
The blended cost of a company's debt and equity.
CAPM (expected return)
What it measures
The capital asset pricing model (CAPM) calculates the expected return of an asset based on its risk (beta) relative to the overall market.
When to use it
Use this to set the cost of equity input for WACC. It shows the return investors should demand for holding a risky stock.
Watch out for
Beta is backward-looking. A stock with low volatility in the past (a low beta) can suddenly become very risky.
CAPM (expected return)
The return investors should expect for a given level of risk.
Return on equity (ROE)
What it measures
Return on equity (ROE) measures how well management generates profit from the money shareholders have put in. Warren Buffett is known to favor it.
When to use it
Use it to judge management quality. A company with a high ROE needs less debt to grow.
Watch out for
Debt can inflate ROE. A company with very little equity because of heavy borrowing can show a very high ROE while being close to insolvency.
Return on equity (ROE)
How efficiently a company turns shareholder capital into profit.
About average.Typical: about 10%
Returns & income
Growth rates and yield analysis.
CAGR
What it measures
Compound Annual Growth Rate (CAGR) smooths out the volatility of an investment's return. It tells you what the annual growth rate would be if it grew at a steady rate every single year.
When to use it
Use this to compare investments held for different lengths of time, such as a stock held for 3 years against one held for 10.
Watch out for
CAGR hides volatility. An investment could crash 50% one year and double the next, and still show a respectable CAGR. Check the path of returns, not only the endpoints.
CAGR
The smoothed annual growth rate over time.
Above the long-run market average.S&P 500 long-run average: about 10%
Dividend yield
What it measures
Calculates the annual percentage return generated by dividends alone, relative to the stock price.
When to use it
Useful for income investors. Compare it with the risk-free rate on government bonds. If a stock yields 2% and a government bond yields 5%, the stock is less attractive for income.
Watch out for
Watch for yield traps. A very high yield, such as 15%, often means the share price has fallen sharply because the market expects the dividend to be cut.
Dividend yield
Annual dividend income as a percentage of the share price.
Tax equivalent yield
What it measures
Calculates the taxable yield required to match a tax-free municipal bond yield. It helps high-income earners compare tax-free and taxable investments.
When to use it
Use it to compare municipal bonds with corporate bonds. In a high tax bracket, a 4% tax-free yield can be worth more than a 6% taxable yield.
Watch out for
This only applies if the bond is actually tax-free for you. State taxes, for example, may still apply.
Tax equivalent yield
Compares tax-free and taxable bond yields.
Real return
What it measures
Calculates your actual purchasing power growth after inflation. If your bank pays 4% but inflation is 5%, you are actually losing money.
When to use it
Use it to assess long-term savings, including high-yield savings accounts.
Watch out for
Compounding works both ways. Negative real returns compound to destroy wealth silently over time.
Real return
Your return after inflation.
Rule of 72
What it measures
A mental math shortcut for estimating how long an investment takes to double in value at a fixed annual rate.
When to use it
Use it for quick checks. At a 12% annual return, money doubles in about 6 years (72 / 12).
Watch out for
It is an approximation and becomes less accurate at very high rates.
Rule of 72
How many years it takes for money to double.
Compound interest
What it measures
Projects how a starting amount plus regular monthly contributions grows when returns are reinvested. Interest starts earning interest of its own, so growth accelerates the longer the money stays invested.
When to use it
Use it to plan long-term saving and investing: retirement accounts, index fund plans, or a child's education fund. Try doubling the time horizon and watch what happens to the interest share.
Watch out for
The rate you enter is an assumption, not a promise. Markets don't return a smooth 7% every year, and inflation quietly eats into the real value of the final number.
Compound interest
How savings and regular contributions grow over time.
Most of the balance now comes from interest rather than deposits.Over 50% from interest
Portfolio & strategy
Risk management and planning.
Kelly criterion
What it measures
The Kelly Criterion calculates the mathematically optimal bet size to maximize long-term wealth growth, given a known edge.
When to use it
Use it for position sizing if you know your historical win rate and payoff ratio.
Watch out for
Betting the full Kelly amount is extremely volatile. Most practitioners use half Kelly (half the recommended amount) to reduce swings and the risk of ruin.
Kelly criterion
The position size that maximizes long-term growth.
FIRE number
What it measures
Calculates the portfolio size needed to retire and live off investment income indefinitely (FIRE stands for financial independence, retire early). It is based on the 4% rule.
When to use it
Use it for long-term financial planning. It gives you a specific target to aim for.
Watch out for
The 4% rule assumes a 30-year retirement. For longer retirements, such as retiring at 40, many planners suggest a more conservative withdrawal rate of 3–3.5%.
FIRE number
The portfolio size needed to retire.
Drawdown & recovery
What it measures
Calculates how far an asset has fallen from its peak and how much it must rise to get back to even.
When to use it
Use it to see how losses and gains are asymmetric. A 50% loss is not recovered by a 50% gain; it takes a 100% gain.
Watch out for
Deep drawdowns do lasting damage to long-term compounding, which is why avoiding large losses matters more than chasing large gains.
Drawdown & recovery
How much a price must rise to recover from a loss.
Average cost (DCA)
What it measures
Calculates your new average purchase price if you buy more shares today. Adding to a position over time like this is often called dollar-cost averaging (DCA).
When to use it
Use it when a stock you own falls in price, to see how many shares you would need to buy to lower your break-even price.
Watch out for
Don't throw good money after bad. Just because you can lower your average cost doesn't mean the stock is worth buying.
Read the guide: Dollar-Cost Averaging: How the Math Actually Works
Average cost (DCA)
Your new average price after buying more shares.