Calculated risk: you know what you could lose and decided it’s worth it. Reckless: you didn’t check.

The difference is not size, it is knowledge. You can be perfectly careful about something huge and completely reckless about something trivial, because the dividing line runs through whether you looked. Checking does not mean removing the danger. It means being able to say, in advance and out loud, what you stand to lose, and having decided the thing on the other side is worth that.

Before the next decision that costs you something, write the worst case in one sentence. If you cannot finish the sentence, you have not checked yet.