Latest posts
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Half Birthday Calculator
Enter a date of birth to find the half birthday — exactly six months on — plus when it next falls and how many days away it is.
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Military Time Converter
Convert 12-hour clock times to 24-hour military time and back, with the spoken form and the two rules everyone forgets.
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Word Counter
Paste any text to count its words, characters (with and without spaces), sentences and estimated reading time — live, in your browser.
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Margin Calculator
Enter cost and selling price to get the gross margin percentage, the profit, and the markup — with the margin-vs-markup difference made explicit.
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Percentage Increase Calculator
Enter an original and a new value to get the exact percentage increase or decrease, with the direction and absolute change shown.
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Child Height Predictor
Estimate a child’s adult height from the parents’ heights with the mid-parental (Tanner) method, with the likely range shown honestly.
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Cat Age Calculator
Convert your cat’s age into human years with the veterinary standard: 15 for the first year, 9 for the second, 4 for each year after.
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Moon Phase Calculator
Pick any date to see the moon’s phase, how far through the 29.5-day cycle it is, approximate illumination, and the next full moon.
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Reverse Percentage Calculator
Know the value after a percentage was applied? Enter it with the percentage to recover the original — for discounts, tax and increases.
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Age Difference Calculator
Enter two dates of birth and get the exact age gap in years, months and days — plus the total days and who is older.