A calculator for the Japanese deviation score (hensachi, 偏差値). Enter each subject's score, the class average and the standard deviation — the figures printed on a test result slip — and it computes the deviation score with the formula 50 + 10 × (score − average) ÷ standard deviation. The deviation score expresses your relative position with the average fixed at 50: 50 is exactly average, 60 is one standard deviation above, 40 is one below. It supports the five Japanese school subjects (Japanese, Math, English, Science, Social studies); leave a row blank to skip subjects you didn't sit, so it works for one subject or five. Subject names are editable, so it also fits mock exams or other subject sets. Alongside each subject's deviation score it shows the average deviation across the subjects entered, the total score and the sum of the averages, so students can quickly check how a regular or practice test went. Computing a deviation score needs the standard deviation as well as the score and average; it is usually printed on the result slip, and if not you can derive it from every classmate's score on the same test. Every calculation runs in your browser; the numbers you enter are never sent to any server or API.