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Free trading calculators
Thirteen calculators for the arithmetic around a position: how many units a risk budget buys, what collateral it ties up, how an option behaves as time and volatility move, what a record of results actually says. US and Indian markets, including NSE lot sizes.
These calculators do arithmetic on numbers you enter. They do not produce recommendations, do not connect to any market feed, and do not know what any instrument is worth — that is never advice, and it is not a substitute for your own judgement or a licensed professional's.
Risk & sizing3
Before the trade: how much, and what it costs to be wrong.
Position Size
Position size calculator
Turn an account balance and a risk percentage into a number of shares, contracts or lots — with India's lot sizes handled properly.
How many units does my risk budget actually buy?
Margin & Leverage
Margin and leverage calculator
Collateral required, effective leverage, free capital left over — and how far price can travel before maintenance.
How far can this move against me before maintenance?
Delta-Adjusted Sizing
Delta-adjusted position size calculator
Size an options position properly: the stop is in the underlying, but the loss lands in the premium, and delta is what connects them.
How many contracts does my risk budget actually allow?
Options & volatility6
How a structure pays at expiry, and how time, volatility and probability shape an option before it gets there.
Options Payoff
Options payoff calculator
Draw the profit and loss of an options position at expiry - break-evens, max profit, max loss - from strikes and premiums you type in.
Where does this position break even, and what is the worst case?
Wheel Cycle
Wheel strategy calculator
Every way one cash-secured put and covered call cycle can end — collateral, cost basis, the called-away result, and the loss if assigned shares fall.
What does each way this cycle can end pay, or cost?
Theta Decay
Theta decay calculator
Watch an option's time value drain day by day with price and volatility held still — and see why the last weeks go fastest.
How fast does this option's time value disappear?
Expiry Probability
Option probability calculator
Model probabilities that a strike finishes in the money, that a position finishes past its break-even, and that the strike is touched along the way.
Under this volatility, how likely is each outcome at expiry?
IV Rank
IV rank and IV percentile calculator
Turn implied volatility readings you already have into IV rank and IV percentile — and see why the two can disagree by thirty points.
Where does this volatility reading sit against its own history?
Earnings Move
Earnings implied move calculator
The move an earnings straddle is priced for, the event's share of implied volatility, and what a volatility crush does to a position the day after.
What move is priced in, and what does the crush cost?
Analysis4
After the fact: what a record actually says, how wide the outcomes of an edge can be, and what a chart's candles describe.
Risk : Reward
Risk-reward ratio calculator
Entry, stop and target become an R:R ratio — and the win rate that ratio needs before it breaks even.
What win rate does this payoff need to break even?
Drawdown
Drawdown calculator
The gain a decline demands back, the arithmetic of a losing streak, and peak-to-trough analysis of a curve you paste in.
What does this decline demand back before it is undone?
Monte Carlo
Monte Carlo trading simulator
Run a win rate and an average win/loss through a thousand sequences to see the spread of outcomes, not just the average one.
How different can the same edge look across a thousand runs?
Candlestick Anatomy
Candlestick pattern analyser
Enter up to three candles and get the anatomy of each — body, shadows, where the close finished — plus the textbook name of the shape or pattern.
What do these four prices actually describe?
Your figures stay in the browser
Balances, entry prices and pasted equity curves are never transmitted, stored or logged. The arithmetic runs locally — there is no request carrying any of it, and no column anywhere that could hold it.
Both markets, properly
US stocks, options and futures alongside Indian cash and F&O, plus forex and spot crypto. Lot sizes, tick sizes, margin models and rupee digit grouping all follow the market you pick.
Specifications, never prices
Typing a symbol fills in its contract specification as of August 2026 — lot size, tick, currency. No quote is fetched, and every seeded figure stays editable because your broker's number is the one that governs.
Frequently asked questions
- Are these trading calculators really free?
- Yes. There is no payment, no card and no paywall on any of the thirteen. A free account unlocks all of them at once, and that is the only thing asked for. They then run as JavaScript in your browser, so they keep working even if you lose connectivity after the page has loaded.
- Do the calculators store or send my numbers anywhere?
- No. Every calculation happens locally in your browser. Account balances, entry prices and pasted equity curves are never transmitted to a server, never written to a database and never logged, and closing the tab discards them. The account you create is an email address and a password — it is not linked to anything you type into a calculator, because none of that is ever sent.
- Do these work for Indian markets as well as US markets?
- Both. Each calculator carries a market selector covering US stocks and ETFs, US options, US futures, Indian cash equities, Indian F&O, forex and spot crypto. Currency formatting follows the market — rupee figures are grouped in lakhs and crores, not thousands — and Indian derivative lot sizes are filled in when you type a symbol.
- Do the tools fetch live prices for a ticker?
- No, by design. Typing a symbol resolves its contract specification — lot size, tick size, currency and margin regime — from a table shipped with the site. It never fetches a price. You size a position at the entry you plan rather than at the current tick, so a live quote adds nothing a planned entry does not already give you, and redistributing exchange price data carries licensing and regulatory conditions this site does not meet.
- Why do I need an account for a free calculator?
- One account unlocks all thirteen calculators and the whole free resource library, and it is what lets the site tell whether these tools are worth continuing to build. It costs an email address and a password — no card, no trial, no expiry. Everything explaining how each calculator works, including the formula and the FAQ, is readable without one.
- Is any of this financial advice?
- No. These are arithmetic tools that operate on figures you type in — the theta, probability and earnings calculators apply the Black-Scholes model to a volatility you supply, and say so. They do not produce recommendations, do not rank instruments, do not propose entries, stops or targets, and do not read market data. The creator is not a registered investment adviser, research analyst or broker with the SEC, FINRA, CFTC, NFA, any U.S. state securities regulator, or SEBI.
- How accurate are the lot sizes and margin rates?
- They are seeds, not authority. Contract sizes and margin regimes are pre-filled from published standards as of August 2026 and every one of them stays editable, because exchanges revise lot sizes and margin requirements and brokers routinely require more than the regulatory minimum. Check the figure against your broker and type in the real one.
⚠ Important disclaimer
These calculators are provided strictly for educational and informational purposes. They perform arithmetic on figures you enter. Nothing on these pages is financial, investment, trading, legal or tax advice, nor a recommendation to buy, sell or hold any security, derivative, commodity or cryptocurrency.
The creator is not a registered investment adviser, research analyst or broker with the SEC, FINRA, CFTC, NFA, any U.S. state securities regulator, or SEBI (as an Investment Adviser or Research Analyst). Trading involves substantial risk of loss — you can lose some or all of your capital, and with leveraged instruments you can lose more than you deposit.
Contract specifications, lot sizes and margin rates shown here are seeded from published standards, are editable, and may be out of date or wrong for your broker. Exchanges revise lot sizes and margin requirements, and brokers routinely impose more than the regulatory minimum. Verify every figure against your own broker before acting on it. These tools carry no warranty of any kind and may contain errors.
You are solely responsible for your own decisions. Read the full legal disclaimer →