Great-circle distance between any two coordinates with the haversine substitution laid out line by line: the half-angle sines, the intermediate a, the central angle in radians and degrees, plus the initial bearing and the midpoint. HAVERSINELATITUDEGEODESY
Drag the angle and read sin, cos, tan and radians to four decimals, with the exact common-angle table and a practice mode.
Weighted grade across assignments, letter and GPA scales, and the mark on the final you actually need to hit your target.
Convert one number into every base at once, with a signed bit-width view, two's complement and a padded hex form.
Score options against weighted criteria with a transparent weighted-sum calculation, normalised weights and a ranked breakdown.
Focus sessions with a chime, right in the tab.
Drag-and-drop tasks saved in this browser.
Cut the background off a photo in your browser — no upload, no watermark.
All 118 elements — tap two to see the compound they form.
