The Estimator will try to give a reasonable timeframe if you give it an activity. It's not exact, it's just a rough guess, but it should give you an idea of what to expect.
The 🌶 spiciness level 🌶 gives the tool a hint about how hard it is for you to concentrate on the activity, or how physically hard you find it. It's not a simple multiplier, it will have a different effect depending on the activity.