Productivity Tools

Twelve small tools for everyday arithmetic, time and writing: a percentage calculator, a tip calculator, a salary to hourly converter, a time card calculator, a meeting cost calculator, a Pomodoro timer, a GPA calculator, an age calculator, a date difference calculator, a unit converter, a word counter and a typing speed test. None of them need an account, and nothing you type leaves the page.

Which tool for which job?

• Everyday numbers. The percentage calculator covers percentage-of, percent change and percent difference, three calculations that are easy to mix up. The tip calculator splits a bill between any number of people, and the unit converter handles length, weight, volume, area, speed and temperature.
• Pay and hours. The salary to hourly converter converts between annual pay and an hourly rate on the standard 2,080-hour working year, and the time card calculator adds up a week of shifts and breaks and splits out overtime pay.
• Time and focus. The meeting cost calculator puts a price on an hour of everyone’s time, and the Pomodoro timer runs focus and break intervals you can lengthen for deep work.
• Dates. The age calculator gives an exact age in years, months and days, and the date difference calculator counts the days, weeks and business days between two dates.
• School and writing. The GPA calculator weights each grade by its credit hours on a 4.0 scale, the word counter counts words and characters and estimates reading time, and the typing speed test measures words per minute and accuracy.

Where these tools make assumptions

A few results depend on conventions worth knowing. The salary converter assumes a 2,080-hour year unless you change the hours or weeks. The time card starts from the federal rule of overtime at 1.5 times pay after 40 hours a week; you can change both numbers, but it only applies a weekly threshold, so daily overtime rules such as California’s are not calculated. The GPA tool uses a standard US 4.0 scale, so schools that weight honours courses or use another scale will differ. Each page states its own assumptions and shows the formula, so you can check the answer by hand.