Three checkpoints in this guide
Follow the full walkthrough in order, or jump directly to one of its main sections.
A trading calculator answers a defined math question from the inputs you give it. It does not verify that your stop, contract specification, fee schedule, account rule, or performance estimate is correct. Choose the calculator by the decision you are making, validate the inputs against the venue or program, and preserve the result beside the trade plan.
What This Tool Does—and What It Cannot Decide
The TSB Tools directory currently contains 22 public calculators and diagnostic tools. They cover sizing, setup math, account-path stress, market-specific costs, and performance review. You do not need to run all 22. You need the smallest tool that matches the next decision.
How large can this position be?
Position Size Calculator returns the size implied by loss budget, stop distance, and value per unit. Verify contract or pip value, currency, fees, slippage, gaps, and venue minimums.
Does the payoff justify the loss?
Risk/Reward Calculator returns reward-to-risk and the zero-cost break-even win rate. Verify commissions, spread, slippage, partial exits, and whether the target is executable.
What does this loss do to the account?
Drawdown Calculator returns peak-to-current loss and recovery required. Verify open risk, withdrawals, deposits, rule-specific equity logic, and path dependence.
Could a funded-account rule be breached?
Prop Firm Calculator builds a rough scenario from entered averages. Resolve the exact program, phase, size, rule version, timezone, order sequence, and current equity.
Where could leverage become dangerous?
Liquidation Calculator produces a model estimate. Verify venue formula, maintenance tier, margin mode, fees, funding, collateral, and other positions.
What does my recorded edge imply?
Expectancy and Kelly derive outputs from estimated probability and payoff. Verify data quality, dependence, regime, uncertainty, and sample membership.
A calculator is therefore a transformation, not an oracle. If two traders enter different assumptions, both outputs can be mathematically correct while only one describes the actual trade.
Find Your Calculator: The Decision Tree
Before entry: control loss and execution
Start with position size when the trade idea already has an invalidation level. The general relationship is:
That relationship is simple; the unit conversion is where errors hide. A forex lot calculation needs the correct pip value and account currency. Futures sizing needs the exact contract multiplier and tick value. Crypto and equities need the price distance, quantity increment, fees, and any leverage or margin constraints. The position-size calculation guide walks through the input contract rather than prescribing one risk percentage to every trader.
Then use risk/reward to describe the planned payoff geometry. If reward is twice the planned loss, the displayed ratio is 2:1 and the zero-cost break-even win rate is 1 ÷ (1 + 2), or about 33.3%. It is a mathematical boundary, not a forecast. Costs and execution shortfall push the required realized win rate higher, while scaling and variable exits can make the simple ratio a poor description of the finished trade.
Before adding leverage: check margin, liquidation, and carrying cost
The Margin Calculator estimates capital required under the assumptions entered. The Liquidation Calculator is useful for seeing how entry, leverage, and direction interact, but “estimated liquidation” must not be treated as the exchange’s executable trigger. Cross margin, maintenance tiers, collateral changes, funding, fees, and other positions can move the actual boundary. The venue’s current contract and risk documentation controls.
For crypto, add the Exchange Fee Comparison, Funding Rate Tracker, and Crypto Profit Calculator when those costs affect the decision. A favorable price target can still produce a weak net result after fees and carrying cost.
For an account path: stress drawdown and exact rules
Drawdown and recovery answer different questions:
The arithmetic is exact for those two balances. A forecast of how the account will travel between them is not. Deposits, withdrawals, open positions, changing risk, correlated losses, and program rules can change the path materially. Use the risk-per-trade guide to convert the output into an account-level loss budget rather than copying a universal percentage.
The public Prop Firm Calculator deliberately produces a rough scenario from average inputs. It is not a verdict on an exact challenge. A real pass, stall, or breach decision needs the selected firm, exact program and phase, region, account size, rule version, evaluation timezone, current state, and trades in chronological order. Use the prop-firm rules guide to identify the rules that must be resolved before relying on any scenario.
For research: calculate expectancy before optimizing size
Expectancy asks what the recorded payoff distribution produced on average:
The Expectancy Calculator can test the arithmetic. The expectancy guide explains the harder part: deciding which trades belong in the calculation and how to preserve uncertainty.
Kelly sizing goes one step further. In its basic binary form, the calculator uses f* = p − q/b, where p is estimated win probability, q is loss probability, and b is the win/loss payoff ratio. A precise output does not make those estimates precise. Dependence between trades, changing regimes, fat tails, estimation error, liquidity, and hard account limits can dominate the formula. There is no magic trade count after which Kelly becomes safe, and the output should never be converted into a universal risk recommendation.
The Three Essential Calculator Jobs
The baseline version named three “essential calculators.” The more durable rule is to cover three jobs:
- Cap the planned loss. Convert the chosen invalidation level and loss budget into a tradable size.
- Test the payoff after friction. Record entry, stop, target, costs, and the break-even boundary before the outcome is known.
- Stress the account path. Check drawdown recovery, simultaneous exposure, and any exact account or program constraints.
Position Size, Risk/Reward, and Drawdown are sensible starting tools because they cover those jobs. They are not mandatory before every possible trade, nor do they create “complete risk management” in a fixed number of seconds. An automated execution system may calculate them upstream; a multi-leg strategy may require a different model; and a venue can reject a mathematically valid size.
Save the calculator name and version, timestamp, inputs, output, source used for contract or rule data, rounding decision, and final order size. That turns a transient number into evidence you can compare with the executed trade.
Calculators by Market
| Market | Common starting tools | Market-specific input risk |
|---|---|---|
| Forex | Position Size, Pip, Lot Size, Currency Converter | Pip convention, quote currency, account currency, lot definition, spread, and rollover |
| Futures | Position Size, Risk/Reward, Drawdown, Prop Firm | Contract multiplier, tick size/value, expiry, exchange margin, commissions, and program-specific drawdown |
| Crypto | Crypto Profit, Liquidation, Exchange Fees, Funding Rates | Venue, product, margin mode, maintenance tier, collateral, fees, funding, and quantity increments |
| Stocks and ETFs | Position Size, Average Cost, Profit, Break-Even | Share quantity, commissions, currency, corporate actions, borrow cost, and gap risk |
The core loss-budget relationship travels across markets; the units and execution rules do not. Do not enter a futures tick value into a forex-lot interface and assume the label will rescue the result. If the tool does not represent the instrument’s actual contract, calculate in money-per-unit or use the venue’s own specification.
Calculators by Trading Activity
Pre-trade planning
Use sizing, pip or tick value, margin, risk/reward, break-even, fees, and liquidation tools while the plan can still be changed without an open-position bias. Save both the initial inputs and any later revision.
Account and rule monitoring
Use drawdown and prop-rule tools with the current account state—not just the nominal starting balance. A static calculator cannot see unrecorded open risk, cross-account exposure, a midnight reset, or a newly revised program rule.
Performance review
Use expectancy, Kelly, average cost, remove-worst-trades, compounding, and audit tools as controlled questions. “What if I remove the worst trades?” is a sensitivity test, not evidence that those trades were avoidable. “What if the account compounds at this rate?” is a projection, not a return promise. The useful output is the assumption that drives the result and the evidence required to accept or reject it.
Turn Calculator Output Into Evidence With TSB
A calculator tells you what follows from the inputs. Trader’s Second Brain helps determine whether those inputs match the trade evidence, whether the plan was followed, and what deserves attention next.
Number without lineage
“Trade 0.8 lots.” The contract input, rule version, rounding, planned stop, and executed order are missing, so the result cannot be audited later.
Decision with lineage
The calculation, assumptions, source, planned size, actual fill, linked trade, rule scope, and later review remain attached to one decision.
Import or reconcile the executed history in Journal, define the intended setup and risk rule in Playbook, and let AI Coach examine the selected evidence set. Coach can flag a mismatch between planned and realized risk, route the issue through data quality, plan compliance, setup risk, market regime, rule testing, or setup-decay lenses, and carry one supported action into Current Focus. When the needed stop, fee, modification, or program evidence is missing, it reports the limitation instead of fabricating precision.
That is the valuable side of Coach: not replacing transparent arithmetic, but making the arithmetic accountable to the trader’s actual record and converting a supported discrepancy into the next test. The user can open the trades behind the conclusion, challenge the scope, and see why the action was proposed.
TSB has processed 600K+ imported trades across its import history, and its source registry recognizes 331 exact broker, exchange, platform, and prop-export profiles. Those figures mean imported trades and recognized source routes—not users, guaranteed compatibility, or trades analyzed by Coach. Route validation and reconciliation still come first.
Choose the calculation Attach it to the trade Turn the evidence into Current Focus
The Bottom Line
Choose the calculator by the decision: size a planned loss, test payoff after friction, stress the account path, resolve exact rules, or evaluate recorded performance. Verify every market- and program-specific input, save the calculation beside the plan, and compare the result with the order that actually executed.
The strongest workflow is calculator → documented assumption → executed trade → reconciled evidence → review. The math becomes mechanical without pretending the inputs are self-validating. TSB then adds the part a standalone calculator cannot: evidence lineage, plan comparison, an inspectable Coach conclusion, and one measurable next action.
Disclosure: Trader’s Second Brain is our product. The 22-tool catalog, calculator formulas, public access, scenario limitations, product workflow, and canonical public-truth values were checked against the local codebase on September 10, 2026. Calculators are educational decision aids, not individualized investment advice or guarantees. Verify contract, venue, tax, broker, exchange, and funded-program requirements at their official sources. See our editorial methodology.
