I built this to fill the gap between phone calculators and complex software like SPSS. StatCalc handles the statistical calculations that students and researchers need most often:

• Descriptive statistics with histogram visualization • Confidence intervals (proper t-distribution) • One-sample t-tests with p-values • Sample size/power analysis

Clean interface, works on mobile, no installation needed. Built with vanilla JS to keep it fast and simple.

Would love feedback on the UI and what other statistical functions would be most useful to add.