You underestimate how long things take.
Here's a tool that corrects it for you.
Russell Barkley calls it time blindness. The ADHD brain struggles to feel how long a task lasts, to plan a day, to anticipate the cost of a project. The result: we systematically underestimate how long something will take, even when we know we underestimate. It's mechanical, not a willpower flaw.
This tool takes your spontaneous estimate and corrects it along four documented factors: startup difficulty, novelty, stimulation level, environment distraction. Plus a minimum floor of 1.5x your original estimate, because Barkley and multiple studies converge on the same point: ADHD adults always underestimate.
Everything runs in your browser. Nothing is sent to a server, nothing is kept. It's free and stays that way.
Startup difficulty. The harder it is to initiate the task, the higher the hidden cost. A 5/5 startup adds 80% to the estimated time. This is what Barkley calls the "task initiation deficit": it's not the task that's hard, it's the shift from inertia to action.
Novelty. A task already done is a task internalized. A new task requires learning the procedure while executing it. A 5/5 novelty adds 60%. That's why writing a fifth monthly report takes less time than the first one, even when the content is identical.
Stimulation. The only factor that can reduce the time. A captivating task (4 or 5 out of 5) recruits attention easily, sometimes into hyperfocus, and perceived time compresses. A weakly stimulating task (1 or 2 out of 5) adds 30% because starting is harder and focus drifts. Hallowell describes this double movement in ADHD 2.0.
Distraction. The environment matters. A chaotic open-space at 5/5 adds 40%. It's mechanical: each interruption costs the time of the interruption plus the time to re-enter the task, and the ADHD brain filters ambient noise less well.
Barkley floor. Whatever happens, the final estimate is at least 1.5x your neurotypical estimate. If you find that frustrating, that's exactly the point. It's the empirical rule of thumb that works in practice: take your spontaneous estimate, add 50%, then adjust with the factors.
For years, I committed to impossible deadlines. I'd see a task, feel like it was "two hours of work", promise delivery for the next day. Three days later, I still wasn't done. Not out of laziness, out of bad math. My brain didn't feel time the way other people's did.
This tool isn't a miracle. It won't make you deliver faster. It will help you promise more accurately, which changes everything in your relationship to work, to others, to yourself. It's what Barkley calls "externalizing your brain": moving the estimate outside of you because inside it's biased.
The coefficients used draw on the adult ADHD literature: Russell Barkley, Taking Charge of Adult ADHD (Guilford, 2010, rev. 2022) and Executive Functions (Guilford, 2012) for time blindness; Piers Steel, The Nature of Procrastination (Psychological Bulletin, 2007) for the stimulation / procrastination relationship; Hallowell and Ratey, ADHD 2.0 (Ballantine, 2021) for the double movement of hyperfocus and drift. The formula stays a practical approximation, not a scientific model.
What this tool is not: a diagnosis, a medical test, a planner. It's a compass, free, to use without pressure.