Popular calculators
The tools that answer the questions people ask most: percentages, loan payments, BMI, age, grades, tips and the handful of unit conversions that come up daily.
All popular tools
Percentage Calculator
Answer all three percentage questions: X% of Y, X as a percent of Y, and the whole behind a percentage.
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Percentage Increase Calculator
Find the percentage rise between two values, or add a percentage to a starting number.
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Percentage Change Calculator
One tool for rises and falls — a signed percentage change measured from the original value.
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Discount Calculator
Find the sale price, the saving and the final cost after a discount — including stacked offers.
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Average Calculator
Mean, median, mode and range from one list of numbers, with the sorted data shown.
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Reverse Percentage Calculator
Recover the original figure from a price that already includes a markup, tax, discount or increase.
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Weighted Average Calculator
Average values that carry different importance — credits, portfolio sizes, category weights.
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What makes these the popular ones
Three things drive a calculator into heavy use: the arithmetic is easy to get subtly wrong, the answer has real consequences, and the question recurs. Percentage change fails the first test constantly — people reach for the wrong base. Loan payments fail the second: a rate entered as 6 instead of 0.06 changes a life decision. Age and date differences fail the third; they come up every time a form asks for something in months.
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