Don’t just give the number. Show the method.
Every calculator explains how its result was calculated, which inputs matter and what assumptions sit behind the maths. If a method is an estimate, it says so.
About WorkItOut.Tools
Calculators that show their work
WorkItOut.Tools is an independent project building practical calculators with editorial standards - useful tools that explain their methods, sources and assumptions, instead of hiding them.
Principles
How we build every calculator
Don’t create a page for every keyword.
We build the best page for each real user problem. Our Sleep Calculator handles bedtime and wake-up questions in one reversible tool, instead of thin clones for each phrasing.
Reversible wherever logic allows.
Most questions run in two directions - “when should I wake?” is the same maths as “when should I sleep?” - so our tools let you calculate either way without losing your settings.
Fast, private, no gatekeeping.
Calculations run in your browser, instantly. No account, no email, no sign-up wall between you and the answer. We never collect your calculator inputs.
Methodology
Where the maths comes from
Each calculator page documents its formulas in plain language and shows the exact arithmetic. Where methods exist in the wild - like the classic 90-minute sleep-cycle method - we implement them faithfully and label their assumptions honestly. Where a method is our own construction, like the flexible-cycle window, we say that too, explain the formula, and mark it experimental.
Health-adjacent guidance (such as recommended sleep durations) is linked to authoritative sources - government health agencies, peer-reviewed consensus statements and established references - directly on the calculator page. Our Methodology sections distinguish researched guidance from our own calculation choices, and every page carries a genuine “last reviewed” date that only changes when a real review happens.
We don't invent credentials, reviewers or clinical validation. If something on this site hasn't been reviewed by a qualified specialist, we won't claim that it has.
The roadmap
WorkItOut.Tools starts with sleep - the Sleep Calculator is live, with nap, sleep-debt, jet-lag, efficiency, shift-work and baby-sleep tools planned next. After that: home & DIY, money, travel, fitness and health, each built on the same reusable calculator system. We only launch a category when its calculators are real.