Calculators
Understanding percentages: calculate a share and compare change
Make sense of percentage amounts, percentage change and percentage points with practical examples for reading and comparing figures.
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Percentage calculatorFeaturedFind a percentage of any number instantly.Discount calculatorFeaturedSee the final price and exactly how much you save.Age calculatorFeaturedCalculate age in years, months, and days for any date.Days between datesFeaturedCount the exact elapsed days between two calendar dates.Date Calculator — Add or Subtract DaysFeaturedWhat date is 30, 60 or 90 days from today? Add or subtract any number of calendar days, including weekends, or choose another start date.Hijri ↔ Gregorian converterFeaturedConvert dates using the arithmetic Islamic civil calendar convention.Time zone converterFeaturedTranslate a local date and time between major IANA time zones.Unit converterFeaturedConvert length, mass, area, volume, speed, pressure, energy, data, and more.
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Calculators
Semester GPA versus cumulative GPA: credits change the answer
Understand weighted averages and combine a new semester with earlier study without mixing grading scales or institutional rules.
Date & time
Age and date differences: decide what you are counting
Separate calendar age, elapsed dates and working days, including calendar choice and inclusive counting.
Color & design
JPEG, PNG or WebP? Choose an image format for the job
Understand transparency, compression and pixel dimensions, then use a practical check before sharing an image.
Converters & PDF tools
Extracting PDF text: distinguish text documents from scans
Identify the content inside a PDF, choose a suitable extraction method and check mixed-direction text and tables in editable output.
Developer tools
QR codes: choose the content and check the destination
Choose useful QR content and test readability and destination before sharing or printing, with a separate check of link safety.
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