Calculators
Six calculators for the sums that come up before a trade or an income decision. Each prints its working line by line, so you can check it and see which input moves the answer most.
- 1
Options
Options Profit CalculatorProfit or loss at expiration for a long or short call or put, with the breakeven and a payoff table.
Background: how much a short put can lose
- 2
Earnings
Expected Move CalculatorThe move an option price implies, from implied volatility or from the straddle, before earnings or any date.
Background: the expected move, defined
- 3
Swing Trading
Swing Trade Risk CalculatorShares from your risk and stop, the reward-to-risk in R, and the win rate the trade needs to break even.
Background: R-multiples
- 4
Prop Trading
Prop Firm Drawdown CalculatorWhere a static or trailing drawdown floor sits after each day, and how much room is left.
Background: trailing drawdown
- 5
Dividends
Dividend Reinvestment CalculatorShares and income over the years with dividends reinvested, against taking them as cash.
Background: dividend reinvestment plans
- 6
Dividends
Dividend Income CalculatorThe portfolio a target income needs at a given yield, before and after tax, or the income a portfolio pays.
Background: living off dividends
Before you trust an output
Every calculator here runs in your browser and sends nothing anywhere. The answers are only as good as the inputs, and the inputs that matter most are the ones you have to estimate: an implied volatility, a dividend growth rate, where your stop goes, how a prop firm measures its drawdown. A calculator will happily turn a guess into a number with two decimal places.
Change one input at a time and watch the output. If a small change in the growth rate doubles the income twenty years out, or a slightly wider stop halves the share count, that sensitivity is the useful result. Knowing which input the answer leans on tells you where to spend your checking time before you act.