Math & Dates tools
Scientific notation, ages, date spans, grades and GPA.
Nothing is uploaded. This tool runs entirely inside your browser tab. Your files and figures stay on your device - we never receive them, so we cannot read, store or lose them.
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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.
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 does not use eval
The scientific calculator parses what you type with a shunting-yard parser instead of handing it to the JavaScript engine. That means your input is read as arithmetic and never executed as code, and it means errors can tell you what is actually wrong - an unbalanced bracket, 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.