Free math calculators and converters
Quick answers to everyday math questions. Percentages, grades, unit conversions, time zones, and more — all in your browser with no sign-up.
Percentage Calculator
Three modes: what is X% of Y, X is what % of Y, and percentage change. Shows the formula and explains the result in plain English.
Use this toolScientific Calculator
Full scientific calculator with sin, cos, tan, log, ln, factorial, and calculation history. Keyboard support included.
Use this toolUnit Converter
Convert between length, weight, temperature, volume, speed, area, energy, and pressure units. All conversions in one page.
Use this toolTime Zone Converter
Convert times across multiple time zones simultaneously. Perfect for scheduling with international clients.
Use this toolGPA Calculator
Calculate your GPA on a 4.0 scale. Add courses with letter grades or percentages and credit hours. Supports weighted grading.
Use this toolGrade Calculator
Two modes: what grade you need on the final, and what your current grade is based on weighted assignments.
Use this toolAge Calculator
Calculate exact age in years, months, and days. Includes next birthday countdown and fun facts about time lived.
Use this toolTip Calculator
Calculate tip amounts and split bills. Quick buttons for standard tip percentages.
Use this toolDiscount Calculator
Calculate the sale price after a discount. Works with percentage off or fixed amount off.
Use this toolDate Calculator
Calculate days between dates or add/subtract days from a date. Shows working days and calendar months.
Use this toolSquare Footage Calculator
Calculate area for rectangles, triangles, circles, L-shapes, and custom polygons. Includes cost estimation.
Use this toolPercentage Change Calculator
Calculate the percentage increase or decrease between two numbers. Shows absolute change and explains in plain English.
Use this toolRelated categories
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Frequently asked questions
Are the math calculators free?
Yes. The math tools are free, browser-based, and do not require an account.
Do conversion pages include static values?
Yes. Programmatic conversion pages include indexable conversion tables for common values as well as an interactive converter.
Can I use these calculators for schoolwork?
Yes, but show your working when required. The tools are best used to check calculations and understand formulas.
Which tool handles multiple unit types?
The Unit Converter handles multiple categories. Individual conversion pages are better for specific searches such as centimeters to inches.