How long does it really take to learn something?
Most learning goals have surprisingly well-documented hour costs. Cambridge English publishes guided-learning-hour ranges for each CEFR level — roughly 95 hours to reach A1 and over 1,000 to reach C2. Certification bodies and prep communities converge on similar ballparks for professional exams: around 100 hours for AWS Solutions Architect Associate, 120 or more for PMP. The number you can't look up is the one this calculator solves for: given your weekly time, when do you actually finish?
The math is deliberately simple — total hours divided by weekly hours, rounded up to whole weeks — because false precision is the enemy of planning. What matters is the order of magnitude: seeing that B2 French at three hours a week is a four-year project, not a six-month one, changes your plan (or your weekly hours) before you burn out instead of after.
Making the hours count
Hour estimates assume reasonably effective study. Two habits keep you on the efficient end of the range. First, spend most of your time on active practice — recalling, speaking, building, solving — rather than re-reading or watching; retrieval is what makes knowledge stick. Second, verify as you go: the most expensive hours are the ones spent re-learning material you thought you knew. That's the failure mode PlanAny was built around — its plans end each step with a Socratic check, so a step is only done when you can actually explain it.