> For the complete documentation index, see [llms.txt](https://docs.tradesurge.co/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tradesurge.co/free-tools/calculators.md).
# Calculators
Three calculators for the maths every prop trader repeats - position size, drawdown room and the consistency rule.
The calculators handle the maths you would otherwise do in your head before every trade. There are three, one for each question that ends accounts when it is answered wrong. They live at `tradesurge.co/tools`.
## Position size calculator
Enter your account size, risk percent, entry and stop. The calculator returns the exact USDT perpetual quantity, the value of 1R and the margin at your leverage. The quantity rounds down to the venue's step size, so it is never oversized.
## Drawdown calculator
Enter your daily and maximum loss limits, on a balance or equity basis, and your current equity. The calculator shows the room left today, the distance to a breach, and what a -1R or -2R day would do.
{% hint style="info" %}
Trailing and static drawdown behave very differently. A trailing limit moves up with your peak equity, so a winning streak shrinks your room. Check which type your firm uses.
{% endhint %}
## Consistency calculator
Enter the profit target and the firm's consistency percentage. The calculator shows the most you can make on your best day, the minimum trading days and the days to target at your daily average.
## Inputs and outputs
| Name | What it means |
| --------------------------- | ---------------------------------------------------------------------------------------- |
| **Risk percent** | The share of the account you lose if the stop is hit. This is 1R. |
| **Step size** | The smallest quantity the venue accepts. Sizes round down to it. |
| **Balance or equity basis** | Whether the limit is measured on closed balance or on live equity including open trades. |
| **Best-day ceiling** | The largest single-day profit a consistency rule allows. |
## In the Platform
The Platform runs the same calculations live for every account, and uses them to size each copy of a trade. See [Set the risk dial](/platform/risk/risk-dial.md).
## Next steps
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