This free To-Do Time Estimator helps you answer a brutally practical question: “How long will my task list actually take?” Add tasks, choose a buffer, pick your focus level, and get a realistic total time, finish time, and a simple plan you can follow. No signup. Everything runs in your browser.
Enter each task and your best guess for minutes. Don’t overthink it — the calculator is designed to “save you from optimism” by adding realistic overhead. Use categories to model context switching (email → deep work → errands usually costs time).
Most people underestimate time for two reasons: (1) they think in “perfect world minutes,” and (2) they forget the invisible time leaks — context switching, small interruptions, slow starts, and the mental ramp-up required for deep work.
The To-Do Time Estimator starts with your raw task minutes (your best guess), then applies three reality layers: focus efficiency (how much of your hour becomes usable work), context switching overhead (the cost of bouncing between categories), and a buffer (the safety margin that keeps your plan from collapsing).
The result is not meant to be pessimistic — it’s meant to be schedulable. If you’ve ever created a plan that looked fine on paper but broke by noon, this tool is the fix: it produces a time estimate you can actually live with.
Let your task list be a set of tasks with estimated minutes. We compute:
Focus level represents how much of your working time is truly productive. If focus is 75%, you effectively need more clock time to produce the same output.
Switching overhead depends on how mixed your day is. The calculator uses a per-task overhead plus an extra overhead when you use multiple categories (because switching from “deep work” to “admin” is rarely free).
The “Reality Check” meter is a friendly sanity score based on how much overhead was needed. High overhead means your list is vulnerable to real life — the meter nudges you to trim or batch.
Tasks: “Reply to emails (25), Pay bill (10), Schedule appointment (10)” = 45 active minutes. With normal focus (75%), light switching, and 20% buffer, you’ll likely get a result near ~80–90 minutes. Why? Because even “small” admin work has friction: logins, searching, decision-making, and tiny interruptions.
Tasks: “Write draft (90), Grocery run (35), Call provider (20), Fix bug (60)” = 205 active minutes. If focus is normal (75%) and switching is heavy, the realistic time can jump to ~5+ hours once overhead and buffer are added. Lesson: mixed days are expensive. If possible, group deep work together and errands together.
Same tasks as above, but focus level drops to 60% (tired, poor sleep, lots of notifications). Your total can balloon. This is not failure — it’s physics. The tool helps you plan a smaller day, so you can still win instead of feeling behind all day.
It’s as accurate as your inputs, then improved by realistic overhead. If you underestimate task minutes, the estimate will still be low — but the buffer, focus, and switching layers reduce the damage. Over a week, your estimates get better because you calibrate your “minutes instinct.”
Start with 20%. If your days frequently get interrupted, use 30–40%. If you work in long quiet blocks (rare meetings, low interruptions), 10–20% is enough.
It’s the percentage of your time that becomes real work output. A 75% focus level means 45 minutes of usable work per hour (the rest is ramp-up, distractions, transitions, and breaks).
Categories model context switching. When you jump between “email/admin,” “deep work,” and “errands,” your brain pays a switching tax. Batching similar tasks reduces that tax.
No. This runs in your browser. If you save plans, they’re stored in your local device storage only.
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A time estimate is useful only if it changes what you do next. Here’s a fast way to use it:
This is how you stop feeling behind: you plan a day you can actually finish.