What a consistency rule is
Some funded-account programs add a consistency rule to the profit target: the best single day may not supply more than a set share of the profit. The idea is to separate steady trading from one lucky day. The rule has no standard form. The share varies between programs, and so does the thing it is measured against, which is why this calculator has two bases.
The two bases
- Share of total profit. Best day ÷ net profit over all days. If the best day is 560 and the net is 1,810, the share is 30.9%. To pass a limit L the net profit has to be at least best day ÷ L, so the profit still missing is best day ÷ L − net.
- Share of the profit target. Best day ÷ profit target. It does not depend on how much you have made so far: the best day simply may not exceed L × target. With a 2,000 target and a 30% cap that is 600.
How the numbers are worked out
profit still needed = best day ÷ limit − sum of all days (if positive)
share of target = best day ÷ profit target, allowed best day = limit × target
On the default ten days (120 340 -80 210 560 90 -150 300 180 240) the net is 1,810 and the best day, day 5, is 560: 30.94% of the net. A 30% limit allows 543, so the best day is over by 17, and the net would have to reach 1,866.67, that is 56.67 more, from other days, to comply. At 40% the best day is within the rule. Moving to the target basis changes the answer: 560 against a 2,000 target is 28.0%, inside a 30% cap.
Why the basis matters
The same days can pass one basis and fail the other. On a total-profit basis, one very big day early followed by flat days keeps the share high until other profit builds up. On a target basis only the size of the best day counts, so a large target gives more room.
What it does not do
It does not know your firm's rules: which days count, whether losing days are included, whether the rule applies per phase, and what happens after a breach are all set by the firm. Read them and enter the numbers they give. For the other prop-firm limits see the daily loss limit calculator, the trailing drawdown calculator and the guide to prop firm drawdown rules.
Keeping the best day in proportion
A single outsized day usually comes from an outsized position. Sizing every trade by the same risk, with the prop firm position size calculator, keeps the days comparable, and the challenge simulator shows how your win rate and payoff play out over a whole attempt. A journal gives you the daily results to paste here.
The formulas
share (total profit basis) = best day ÷ net, valid when net > 0
profit still needed = max(0, best day ÷ limit − net)
share (target basis) = best day ÷ profit target, allowed best day = limit × target
The rule is met when the best day is at most the allowed amount. A day exactly at the limit passes.
Worked examples
One big day, total profit basis
Days of 100 200 150 500 50: the net is 1,000 and the best day is 500, 50% of the net. A 30% limit needs 1,666.67 of net profit, so 666.67 more; a 40% limit needs 250 more; a 50% limit is met.
Even days
Days of 220, 180, 240, 160 and 200: the net is 1,000 and the best day is 240, 24% of the net, comfortably inside a 30% limit.
Target basis
The same five days against a profit target of 1,000: a 40% cap allows 400, so the 500 day is 100 above it. A 50% cap allows 500 and is met.
Frequently asked questions
What is a prop firm consistency rule?
A rule that limits how much of your profit a single day may supply, to favour steady results over one lucky day. Each program sets its own percentage and its own base.
How do you calculate the consistency rule?
Divide the best day's profit by the base. The base is either the total net profit or the profit target, depending on the program. If the result is above the allowed percentage the rule is not met.
Is it measured against total profit or the profit target?
Both exist. This calculator has both bases so you can match the one in your firm's rules, which you must read yourself: the arithmetic here does not know your firm.
How much more profit fixes a breached rule?
On the total-profit basis, with the best day unchanged, the net profit has to reach best day ÷ limit, so the missing amount is that minus your current net. Profit on other days counts, a bigger best day makes it worse.
Does a losing day count?
That is set by the program. This calculator keeps losing days in the net result and takes the best day as the single biggest profit. If your firm treats losing days differently, adjust the list you enter.
Is this financial advice or a statement of any firm's rules?
No. It does arithmetic on the numbers you enter. It names no firm and states none of their rules, and trading carries a risk of loss.
Consistent days start with consistent size.
A rule that caps one big day rewards steady risk. These indicators help you mark the levels that keep each trade's stop in the same place.
Premium indicators come with a 7-day free trial on request: how the trial works.
Guides that explain it
Last updated November 2026. For education only. Not financial advice. Results depend on your inputs and cannot predict future performance.