Calculators, converters, text utilities, and more — fast, private, no sign-up, no installs. Everything runs right here in your browser.
Test yourself on All topics with hard questions — instant feedback and an explanation for every answer.
Compute the standard deviation of a data set — sample or population — with variance, mean, and count.
Open toolPretty-print or minify any JSON document instantly, with clear line/column error reporting.
Open toolFind X% of a number, work out what percent one number is of another, and measure percentage change — instantly.
Open toolEnter TP, FP, FN, and TN and get every derived metric: accuracy, precision, recall, specificity, F1, and more.
Open toolCompute your grade point average on the standard 4.0 scale from your course credits and letter grades.
Open toolCount words, characters, sentences, and paragraphs in any text — with reading and speaking time estimates.
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