Consistency rule calculator for prop firm traders

How to use it

1. Tap a preset under "Typical rules" if one is close to your account: 1-step, 2-step, Instant funding or Futures end of day. Each fills a common rule percentage. They are generic examples, not any firm's rules, so adjust the number to match yours. 2. Pick your account currency. 3. Paste or type your daily results, one per line or separated by commas. Enter losing days with a minus sign, for example -250. The tool confirms how many days it read and their total. 4. Enter the rule as your firm states it, for example 30%. 5. Choose what the rule is measured against: total profit or the profit target. For the target, enter the target amount.

The result updates as you type. Copy result puts the answer on your clipboard, and Copy share link copies an address that holds only your inputs.

What the result means

A consistency rule stops one large day from carrying a whole challenge or reward cycle. The tool adds up your days, finds the biggest day, and shows its share of the total.

• Fits the rule: the best day's share is at or below the limit.
• Breaks the rule: the share is above the limit. When the rule is measured against total profit, the tool also shows the total you would need for the best day to fit, with no bigger day on the way. That figure is the best day divided by the limit.

The total is net of losing days, because losses reduce your profit. A losing day therefore makes the rule tighter, not looser.

Measured against total profit, the limit moves as you trade. Measured against the profit target, it is a fixed amount you know from day one: the target times the limit.

Worked example: a futures account with a losing day

A futures trader has five days: $900, minus $300, $500, $1,400 and $600. The firm uses a 40% rule against total profit.

1. Total: 900 minus 300 plus 500 plus 1,400 plus 600 is $3,100. 2. Best day: $1,400, the fourth day. 3. Share: $1,400 divided by $3,100 is 45.2%. That is over 40%, so the days break the rule. 4. Total needed: $1,400 divided by 0.40 is $3,500. The trader needs $400 more profit, with no day above $1,400, for the best day to fit.

Now suppose the firm measures against a $3,000 profit target instead. $1,400 divided by $3,000 is 46.7%, still over 40%. Under that version, no single day should make more than 40% of $3,000, which is $1,200.

Without the losing day the total would be $3,400, and the share would be 41.2%. The minus $300 day added 4 points to the share.

Common mistakes

• Leaving out losing days. Most firms count net profit. Dropping losses makes your share look smaller than the firm's figure.
• Using the wrong base. Total profit and the profit target give different answers for the same days. Check which one your firm uses.
• Splitting days in your own time zone. The firm's daily cutoff decides which day a trade belongs to. A late trade can move into the next day.
• Planning a big day near the end. Late in a cycle, one large day can push the share over the limit after weeks of steady trading.
• Confusing a share rule with a fixed cap. Some firms limit a day to a set amount instead of a share. This tool checks shares.
• Ignoring the other rules. A day that fits the consistency rule can still break the daily loss limit on the way. Check today's floors in the drawdown calculator.

What to check at your firm

• The percentage. Limits of 20%, 30%, 40% and 50% are all in use.
• Which stage it applies to: the challenge, the funded account before a reward, or both.
• The base: total profit or the profit target, and whether profit is net of losing days.
• What happens if you break it. Some firms fail the account. Others ask you to keep trading until the share falls under the limit.
• How a day is defined, including the cutoff time and any minimum trading days.

Results depend on the inputs you enter, and firms' rules differ, so check your own firm's rules before you trade. To see what a steady month could mean after the profit split, try the reward projection calculator. To see how often a strategy reaches the target at all, try the challenge pass probability simulator.

Running a prop firm? Read How to start a prop firm in 2026: tech, legal setup and a 90 day launch plan.