Investing Tools
Investing math, done right.
15 free calculators for stock investors — from dividend yield and P/E to Sharpe ratio, beta, and portfolio rebalancing. Every formula runs in your browser; nothing is sent to a server, no signup, no ads on the math itself.
Dividend Yield Calculator
Compute annual dividend yield from share price and per-share dividend.
CAGR Calculator
Compound annual growth rate — smooth an investment's return over multiple years.
Stock ROI Calculator
Total return on a stock trade — includes dividends and fees.
Dollar-Cost Averaging Calculator
Simulate DCA: fixed periodic investment into a stock or fund.
P/E Ratio Calculator
Price-to-earnings ratio from share price and earnings per share.
Stock Split Calculator
Compute post-split share count, price, and adjusted cost basis.
DRIP Calculator
Dividend reinvestment growth — compound share count over years.
Options Profit Calculator
Profit/loss for a single call or put option at expiration.
Portfolio Rebalance Calculator
Compute buy/sell amounts to hit a target allocation across up to 6 assets.
Sharpe Ratio Calculator
Risk-adjusted return: excess return per unit of volatility.
Beta Calculator
Compute a stock's beta from its returns and a benchmark's returns.
EPS Growth Rate Calculator
Annualized earnings-per-share growth from start-year and end-year EPS.
SIP Calculator
Systematic Investment Plan — final corpus from monthly contributions, expected return, and duration.
SWP Calculator
Systematic Withdrawal Plan — how long a corpus lasts if you withdraw a fixed amount monthly.
Lumpsum Investment Calculator
Future value of a one-time investment at a given annual return over a set number of years.
Which calculator you probably need
If you own a dividend-paying stock and want to compare it to alternatives, start with Dividend Yield. If you are trying to decide whether reinvesting those dividends is worth it over a long horizon, run the DRIP simulation — share count can double from reinvestment alone at a 4% yield across 30 years. For funds or portfolios where you want the equivalent smooth annual return over multiple years, use CAGR; that is the number analysts quote when they say a strategy "returned X% per year." If you are comparing two portfolios with different risk profiles, use Sharpe Ratio — a portfolio with a higher raw return but a much higher standard deviation is not automatically better.
Fundamental analysis math
P/E Ratio and its inverse, earnings yield, are the two most common valuation inputs on Wall Street. Trailing P/E uses the last four reported quarters of EPS; forward P/E uses analyst estimates for the next year. Compare a stock's P/E to its own five-year median and to its sector — an above-median P/E means investors are paying a premium for expected growth. EPS Growth Rate answers whether that expected growth actually shows up in the numbers; if EPS grew from $2.00 to $3.50 over four years, that is a 15% compound annual rate — respectable for a mature company, sluggish for a growth story trading at 40× earnings.
Position-level math
When you actually buy or sell shares, use Stock ROI to compute your true return including dividends and commissions — price change alone systematically understates real return. Stock Split handles the bookkeeping for splits and reverse splits: share count and price adjust proportionally, but your per-share cost basis needs the same adjustment or you will misreport gains at tax time. For a portfolio that has drifted from its target allocation, Portfolio Rebalance tells you exactly how many dollars to buy or sell of each holding to get back to target — a disciplined way to sell winners and buy losers.
Strategy sims
Dollar-Cost Averaging simulates buying a fixed dollar amount at regular intervals — the average cost per share is generally lower than the arithmetic mean of the prices because you buy more shares when prices are low. This is a planning aid, not a backtest; for a real backtest you would need historical prices, not a linear interpolation. Options Profit handles single-leg long or short calls and puts at expiration. Long call breakeven = strike + premium; long put breakeven = strike − premium. Short positions flip the sign of everything and have unbounded loss on short calls; if you are new to options, paper-trade first. Beta measures a stock's sensitivity to broad-market moves — beta of 1 tracks the market, beta of 1.5 amplifies market moves by 50%, beta of 0.5 dampens them by half. R² tells you how much of the stock's variance is actually explained by the market; a low R² means beta is unreliable for that particular stock.
Related calculators elsewhere on ScoutMyTool
For personal-finance basics that pair well with investing math, see Compound Interest, 401(k), and the Capital Gains tax calculator (tax cost of selling matters a lot for after-tax returns). For real-estate investing math specifically, our Cap Rate, Rental Cash Flow, and HELOC calculators live under the calc registry. FIRE-planning tools — FIRE Number, 4% Rule, Coast FIRE — are also there.
Not investment advice
These calculators compute standard finance formulas — dividend yield, CAGR, Sharpe ratio, and so on. They do not recommend stocks, predict future returns, or account for taxes, transaction costs, or slippage unless a field asks for them explicitly. Past performance does not guarantee future results. If you are making decisions with real money, consult a licensed financial advisor. Use these tools as a math aid, not a strategy.
More free tools on ScoutMyTool
Other free tool clusters worth a look — all browser-based, no signup, no ads on your workflow.