Watts to Ergs Per Second (W to erg/s)

1 watt equals 10,000,000 ergs per second exactly.

How to convert watts to ergs per second

To convert watts to ergs per second, multiply the number of watts by 10,000,000. This factor is exact. To go the other way, multiply ergs per second by 1×10⁻⁷.

ergs per second = watts × 10,000,000

Example: 10 watts = 100,000,000 ergs per second.

Several different horsepower units exist. This site lists mechanical (745.7 W), metric (735.5 W) and electrical (746 W) horsepower separately.

About these units

Watt (W)

Metric (SI)Current unit

The SI unit of power: one joule per second. A typical LED bulb uses 5–10 W and a laptop 30–60 W.

Credit for the name goes to C. William Siemens, who proposed it in August 1882 in his presidential address to the British Association for the Advancement of Science. He chose it to honor James Watt, the Scottish inventor who in 1776 improved the Newcomen steam engine. An International Conference on Electric Units and Standards adopted Siemens' definition in London in October 1908 as the international watt. After the 1948 General Conference on Weights and Measures the unit was redefined in absolute terms, and in 1960 the 11th General Conference adopted it into the SI as the unit of power.

Today one watt is one joule per second, or equivalently one volt times one ampere. Orders-of-magnitude tables put an LED light bulb at about 7 W and an adult's basal metabolic rate at roughly 100 W. A 100 kg person climbing a 3 m ladder in 5 seconds works at about 600 W, while a laborer can sustain around 75 W over an eight-hour day. The watt measures a rate, so it says how fast energy is being used, not how much has been used in total.

The watt is the reference unit for power on this site.

Sources: Wikipedia: Watt; Wikipedia: Orders of magnitude (power)

Erg Per Second (erg/s)

CGS & old metricTraditional unit (still used in some regions)

Exactly 10⁻⁷ watts, the CGS unit of power. Used for the luminosity of stars.

Erg per second is simply the erg divided by the second, a rate of energy use that forms the power unit of the centimeter-gram-second system. In base units it is 1 g cm2/s3, and it equals 10 to the power minus 7 watt, a tenth of a microwatt.

The system goes back to the committee of the British Association for the Advancement of Science in 1873, which recommended the centimeter, gram and second as fundamental units. Power in this system never received a special name, which is why the awkward compound form remained in use.

One watt is therefore 10 million erg/s. The small size means everyday machines look huge in these terms, and the unit is mostly met where very large outputs are discussed, such as luminosities in astrophysics, where Gaussian CGS units are still common.

1 erg per second = 1×10⁻⁷ watts (exactly).

Sources: Wikipedia: Centimetre-gram-second system of units; Wikipedia: Erg (unit); NIST SP 811, Appendix B.8 conversion factors

Related conversions

See all power units.