Crypto position sizing starts with the loss you are prepared to review, not with the largest position a platform will allow. Size connects an entry, an invalidation point, an account value, and a planned amount of risk. It is separate from how confident a trade feels.
This article uses position sizing as an educational framework, not as a personal recommendation. There is no universal percentage that fits every person, account, market, or platform.
The basic relationship
The distance between entry and invalidation tells you how much price movement the plan allows. Position size determines how that distance becomes an account result. In simplified form:
position size = planned loss ÷ distance from entry to invalidation
For a long position, invalidation is usually below entry. For a short position, it is usually above entry. Use the absolute distance in the calculation and keep the units consistent.
For example, suppose a practice account uses a $60 entry, a $57 invalidation, and a planned loss of $30. The price distance is $3, so the position size based on that simple assumption is 10 units. This is an illustration of the relationship, not a recommendation to risk $30 or to use a particular market.
Choose invalidation before size
A common mistake is choosing a position first and then moving the invalidation to make the loss fit. That reverses the planning process. Start with the reason for the trade and the condition that would show it is no longer useful. Then calculate how much size fits the chosen plan.
If the resulting size is too small to interest you, that is information. You can wait, change the setup, or skip the trade. Do not automatically move the invalidation closer simply to increase size; a level that no longer represents the idea is not a meaningful risk point.
Leverage is not a sizing method
Leverage changes the margin required for a position and can increase exposure. It does not tell you how much you should risk. Kraken's position-sizing guidance makes the same distinction: position size should come from the planned risk and stop distance, not from the leverage setting.
In a simulator, record leverage or margin assumptions separately from the position size. A small price move can create a large account change when exposure is large. Practice is useful when it makes that relationship visible rather than when it encourages a larger number.
Include costs and incomplete assumptions
Fees, spread, funding, and execution rules can affect the result. The exact costs depend on the platform and product. If the simulator does not include one of them, record the limitation instead of presenting the result as precise.
The position size calculator can help check the arithmetic. The crypto profit calculator can show how a price move interacts with position value. Neither calculator knows whether your invalidation makes sense or whether the exercise is appropriate for you.
Practise with three examples
Create three practice plans using the same account rule:
- a long with a relatively close invalidation;
- a long with a wider invalidation; and
- a short with the same planning process reversed.
Compare the resulting sizes and planned losses. Then add a fee assumption and see what changes. The aim is not to find the most attractive example. It is to learn how the same rule behaves when the chart and direction change.
Review after the trade
When the exercise ends, ask whether the entry, invalidation, size, and cost assumptions stayed unchanged. Did you increase size after a win? Did you reduce the planned loss by moving the invalidation? Did the position feel larger than expected?
Read the crypto risk-reward ratio guide to connect size with target and invalidation planning. A reviewable position size is one that makes the original risk assumptions easy to see. It does not guarantee that the trade will work.