how tall was the first alarm clock

The first known mechanical alarm clock that historians usually point to was about 19 inches tall (around 48 centimeters).

What that “first alarm clock” was

• The device most often cited is a 15th‑century German iron alarm clock from Nuremberg with an open metal framework and a bell on top.

• Descriptions of this clock state that it measured roughly 19 inches in height and was designed to hang on a wall so the driving weights had room to drop.

A bit of context

• Earlier timekeeping devices (water clocks, candle clocks, tower clocks) could signal times, but the Nuremberg iron clock is one of the earliest surviving domestic alarm clocks with a built‑in alarm mechanism.

• Later inventions, like Levi Hutchins’s 1787 alarm clock in New Hampshire and Antoine Redier’s 1847 adjustable alarm clock, came centuries after that tall iron design.

TL;DR: The earliest commonly cited mechanical alarm clock was about 19 inches (48 cm) tall.

Information gathered from public forums or data available on the internet and portrayed here.