Statistics Calculator

This tool computes descriptive statistics for an arbitrary list of numbers. Paste or type numbers separated by spaces, commas, semicolons, or newlines, and it immediately produces count, sum, mean, median, mode, range, standard deviation, variance, and quartiles (Q1, Q3, IQR).

1. Type or paste your numbers into the textarea (any mix of spaces, commas, semicolons, or newlines is accepted). 2. The numbers list and statistics recompute live as you type. 3. Read the Count line to confirm how many values were parsed. 4. Read the statistics grid: Mean, Median, Mode, Std Dev, Variance, Min, Max, Range, Sum, Q1, Q3, IQR. 5. If the textarea has content but no valid numbers were parsed, an error message is shown.

Mean = Σx / n. Median = middle value (or average of the two middle values for even n) of the sorted list. Mode = value(s) with the highest frequency (multiple modes returned comma-separated). Variance = Σ(x − mean)² / n (population, not sample). Std Dev = √variance. Range = max − min. Q1 = sorted[floor(n × 0.25)], Q3 = sorted[floor(n × 0.75)], IQR = Q3 − Q1. Numbers are parsed with parseFloat and split on /[\n,\s;]+/.