Free trader tools. No signup. No noise.
16 battle-tested calculators traders use before they enter a position. Built by the team behind MindTrajour — open to anyone.
Iron Condor Calculator
Punch in your four strikes, the net credit, and the number of contracts. We give you back the max profit, max loss, both break-evens, and a payoff diagram that shows exactly where the trade lives or dies.
Open calculatorOptions math
Spread math, breakevens, IV — without the spreadsheet gymnastics.
Iron Condor Calculator
Punch in your four strikes, the net credit, and the number of contracts. We give you back the max profit, max loss, both break-evens, and a payoff diagram that shows exactly where the trade lives or dies.
Open toolCredit Spread Calculator
Pick bull put or bear call, enter the two strikes and net credit, and read max profit, max loss, break-even, and risk-to-reward in seconds. Use this when your edge is premium collection, not a big directional move.
Open toolDebit Spread Calculator
Pick bull call or bear put, enter strikes and net debit, and get max profit, max loss, break-even, and payoff shape in one read. Use this when you expect a directional move and want defined risk.
Open toolProbability of Profit Calculator
Pick a method — delta-based for a quick estimate, IV-based for a sharper one — and the calculator returns the probability the trade is profitable at expiration. Both methods exist for a reason; using both is how serious option traders cross-check.
Open toolMulti-Leg Break-Even Calculator
Define up to four option legs — calls or puts, long or short, any strike, any premium. The calculator finds every break-even, the maximum profit, and the maximum loss across the underlying's plausible range.
Open toolIV Percentile + Theta Decay
Two of the most-quoted, least-understood numbers on an option chain — IV percentile and theta decay. Plug in the basics and the calculator visualises both, so you can sense-check whether premium is actually worth selling.
Open toolRisk management
Stop guessing. Size, risk, and stop logic — wired to your equity.
Risk/Reward Calculator
Pick a direction, drop in your entry, stop, and target. We hand back the dollar risk, the dollar reward, the R-multiple, and — the number every trader should know cold — the win rate you need to break even at this risk/reward.
Open toolCRV vs Break-Even PoP Table
This table converts CRV directly into the minimum win rate (or PoP) required to break even. Use it as the bridge between trade structure and probability.
Open toolKelly Criterion Calculator
Drop in your win rate, average win, and average loss. The calculator returns the full-Kelly stake — and the half- and quarter-Kelly versions that disciplined traders actually use, because full-Kelly drawdowns are real and brutal.
Open toolRisk of Ruin Calculator
Punch in your starting balance, win rate, average R and a horizon of trades. We run two calculations side by side: the closed-form risk of ruin (when bets are symmetric) and a 1000-trial Monte Carlo simulation in a web worker — so you see the realistic distribution, not just the headline.
Open toolMargin Calculator
Tell us the position size you want to take and the leverage your broker offers. We hand back the deposit your broker locks (required margin), and — if you provide your account balance — the free margin you have left and the utilisation as a percent of equity.
Open toolPosition Size Calculator
Punch in your equity, the percent you want to risk, your stop distance, and the pip value. We give you back the lot size that actually keeps you alive — not the one your gut wants you to take.
Open toolLot Size Calculator
Drop in your position size in units and the calculator returns the equivalent in standard, mini, and micro lots. Useful when your broker quotes one and your strategy thinks in another, or when you're translating a position-size output into something you can actually order.
Open toolPerformance
Win-rate, expectancy, R-multiples — calculators that turn raw P&L into signal.
Drawdown Calculator
Punch in your account's high-water mark and where it sits today. We give you back the dollar drawdown, the percent drawdown, and — the part most traders ignore — the percentage gain you now have to make on the smaller balance just to get back to flat.
Open toolCompound Calculator
Punch in your starting balance, an honest monthly return, the years you want to model, and any monthly contribution. The calculator runs the future-value math and shows the year-by-year balance — so you can see how much of the final number is your contributions and how much is actual edge.
Open toolBreak-Even Calculator
Drop in your win rate, your average win, and your average loss. We give you back the win rate you need to be at break-even given your average R, the edge you currently have over that line, and how many average trades it takes to recover from one average loss.
Open toolThese tools are great. Pair them with a journal.
MindTrajour logs every trade in under 60 seconds and connects the math you ran here to the outcome you actually got. That's where the edge compounds.
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Frequently asked questions
About the tools and why they're free.