Prop Firm Challenge Planner

Read the marketing for an evaluation account and the number on the page is the profit target. Read the contract and the target turns out to be the easy part. Underneath it sit two drawdown rules, and one of them — the daily loss limit — can end an attempt on an ordinary bad session while the account is still up on the month.

This planner simulates the whole thing: your win rate, your reward-to-risk and your position size, run against the actual rule set, thousands of times. It reports where attempts die rather than only whether they pass, and it sweeps position size to show which one gives the best odds under those specific rules.

It is not affiliated with, and does not recommend, any evaluation programme. It is arithmetic applied to rules you can read in a contract.

Why the daily limit is the real rule

A total drawdown limit is a marathon constraint: you have to be wrong many times, over many days, to reach it. A daily loss limit is a sprint constraint, and it resets every session, which means you are exposed to it once per trading day for the entire length of the challenge.

Work an example. A 5% daily limit against 1.5% risk per trade means four consecutive losses ends the day, and four losses in a row inside one session is entirely ordinary at any realistic win rate. Raise the risk to 2.5% and two losses do it. Now look at the sweep table above: the “fail: daily limit” column is flat at zero and then jumps to over forty per cent between two adjacent rows, long before the total drawdown column moves at all.

This is why over-sizing is so much more lethal in an evaluation than in your own account. In your own account a bad day is a bad day. Here it is the end of the attempt and the fee.

The check worth running first

Before anything else, multiply your risk per trade by the number of trades you take in a session, and add a little for costs. If the answer is smaller than the daily loss limit, you cannot breach that limit even by losing every trade you take — and the only rule that can end the attempt is the total drawdown. At 1% risk over four trades, a 5% daily limit is unreachable by arithmetic. At 1.5% it is not, and the tool will tell you which side of that line you are on.

That single boundary explains the shape of the sweep table, and it is the most actionable thing on this page. Below it, failures come only from the slow rule and you have as many sessions as the time limit allows. Above it, one bad afternoon is enough.

Static versus trailing drawdown

The single most expensive detail in these contracts, and the one most often skimmed.

• Static: the floor is fixed at the starting balance minus the limit. Every dollar you make moves you further from it, so the account gets safer as it grows.
• Trailing: the floor follows your high-water mark. Making money moves the floor up with you, so a profitable run does not buy any room — and a normal give-back after a good week can breach a limit you never came close to on day one.

Switch the dropdown between the two with everything else held constant. The gap is usually worth several percentage points of pass probability — less than position size moves it, but it is a term in the contract rather than a choice you make, and it costs nothing to check before you buy.

The size that maximises your odds is smaller than you think

There is a genuine optimum and the table finds it, but it is not where intuition puts it. Too small and the profit target is out of reach inside the time limit. Too large and the daily limit collects you first. In practice the peak sits at the largest size at which the daily limit is still unreachable — right up against that boundary and not one step past it. Move one row further down the table and the pass rate does not decline gently; it falls off a cliff, because a different rule has just come into play.

Note what the optimum is not: it is not the size that makes the most money in your own account. Evaluation rules are a different optimisation problem, because a drawdown here is not a setback, it is an absorbing barrier. If you want the same maths without the artificial rules, the risk of ruin calculator answers it for your own capital.

Be honest about the inputs

Everything on this page is downstream of two numbers: your win rate and your realised reward-to-risk. Almost every trader who runs this tool types in what they hope those numbers are. The result is then a simulation of somebody else's trading.

Both figures come out of a trade log, not memory. If you have one, the trade journal analyzer will compute your real numbers from it in a few seconds. If you do not have one, that — and not the challenge — is the thing to fix first, because a challenge does not create an edge, it only reveals whether one already existed.

What this model leaves out

• Consistency and scaling rules. Many programmes cap the share of profit that may come from a single day, require a minimum number of trading days, or restrict news trading. Each rule only lowers the pass probability shown here.
• Retries. Passing on the third attempt has a cost: the fee, three times.
• The funded stage. Passing is not the end. The same drawdown rules usually apply to the funded account, so the numbers above describe the beginning of the constraint, not the end of it.
• Behaviour under pressure. The simulated trader never sizes up on the last day to reach a target. Real ones do, and it is where a large share of otherwise passable attempts are lost.