How many lots can I trade with $50,000?

Could you please elaborate on how the calculation of tradable lots is determined with a capital of $50,000? What factors come into play, and how does one go about determining the maximum number of lots they can trade with such an amount? Is there a standard formula or does it vary depending on the specific financial instrument and market conditions? I'm particularly interested in understanding the relationship between lot size, leverage, and risk management in this context.