9 tools Math & Dates
Scientific notation, ages, date spans, grades and GPA.
Your files stay on your device. The tool works directly in your browser, using your device to process your files. Nothing is sent to our servers, and we never receive, store, or see your files or figures.
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Age calculator
Find an exact age in years, months and days from any date of birth, plus the total in weeks, days and hours and the countdown to the next birthday.
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Date calculator
Count the days, weeks and working days between two dates, or add and subtract days, weeks, months and years from any date.
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Scientific calculator
A full scientific calculator with trigonometry, logarithms, powers, roots and factorials. Type expressions directly or use the keypad.
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GPA calculator
Calculate a grade point average from any number of courses on the unweighted 4.0 or weighted 5.0 scale, with credit hours taken into account.
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Grade calculator
Work out your current weighted grade from assignments completed so far, and find the score you need on what remains to hit a target.
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Time calculator
Add or subtract durations, or total a whole list of them, in any format people actually type: 1:30, 90m or 1h 30m.
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Hours calculator
Total a week of shifts from start and end times, subtract breaks, handle overnight shifts, and optionally calculate gross pay with overtime.
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Countdown timer
Count down live to any date and time, with days, hours, minutes and seconds, plus working days and the weekday it falls on.
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Time zone converter
Convert a time across as many cities as you need at once, with daylight saving resolved for the actual date you entered.
Arithmetic that respects the calendar
Date maths is deceptively hard. Months have different lengths, leap years break the pattern every four years except when they do not, and "one month later" has no single correct answer. The age calculator and date calculator handle these cases explicitly and say what convention they follow, rather than quietly picking one.
A calculator that reads, never runs
The scientific calculator reads what you type as arithmetic and nothing else. Your input is never executed as code, which is both safer and more useful: errors can tell you what is actually wrong, whether an unbalanced bracket or a missing operand, rather than failing silently.
Grades and averages
The GPA calculator and grade calculator answer different questions. GPA weights whole courses by credit hours across a transcript. The grade calculator weights assessments within a single course, and works backwards to tell you what you need on what remains.
Both are worth understanding rather than just using, because the arithmetic explains where your effort has the most leverage, and sometimes where it has none.
