ルーメン
Embed This Widget
Add the script tag and a data attribute to embed this widget.
Embed via iframe for maximum compatibility.
<iframe src="https://unitfyi.com/iframe/glossary/lumen-def/" width="420" height="400" frameborder="0" style="border:0;border-radius:10px;max-width:100%" loading="lazy"></iframe>Paste this URL in WordPress, Medium, or any oEmbed-compatible platform.
https://unitfyi.com/glossary/lumen-def/Add a dynamic SVG badge to your README or docs.
[](https://unitfyi.com/glossary/lumen-def/)Use the native HTML custom element.
定義
SI組立光束の単位で、光源から毎秒放射される可視光の総量を測定する（1 lm = 1 cd·sr）。
解説
A 60-watt incandescent bulb emits about 800 lumens; an equivalent LED uses only 8–10 watts for the same output. A candle produces roughly 12–13 lumens. Unlike watts (which measure power input), lumens measure actual light output — making them the correct metric for comparing bulb brightness across different technologies.
RELATED ARTICLES
From milligrams to metric tons, this guide covers every major weight and mass unit with exact conversion factors, real-world examples, and a clear explanation of why weight and mass are not the same thing.
Temperature Scales Explained: Celsius, Fahrenheit, and KelvinA complete guide to the four temperature scales in scientific and everyday use—Celsius, Fahrenheit, Kelvin, and Rankine—including their history, conversion formulas, and where they intersect.
Power Units Guide: Watts, Horsepower, and BTU/HourPower is the rate of energy transfer — how fast work is done. This guide covers watts, kilowatts, megawatts, horsepower, and BTU/hour with real-world context from light bulbs to power plants.