Convert Therms to Millijoules

Convert Therms (thm) to Millijoules (mJ) instantly and accurately.

Conversion Formula

mJ = thm × 105505585300

About Therms

A therm is the US natural gas billing unit equal to exactly 100,000 BTU = 105,505,585.262 J ≈ 105.5 MJ. One CCF of average US pipeline gas contains ~1.02 therms. The EIA publishes residential gas prices in $/therm; spot prices at Henry Hub are in $/MMBTU (1 MMBTU = 10 therms). US households average 500-700 therms/year for space heating, water heating, and cooking. A 15 kW domestic boiler running 2 hours delivers ~1 therm of useful heat. 1 therm = 100,000 BTU = 105.506 MJ = 29.307 kWh = 25,200 kcal.

About Millijoules

A millijoule (mJ) is 10⁻³ J - the scale of surgical lasers, spark ignition, and the kinetic energy of small everyday objects. Nd:YAG lasers for ophthalmology and tattoo removal deliver 10-200 mJ per pulse. The minimum spark energy to ignite methane-air is ~0.29 mJ; an automotive spark plug discharges 30-60 mJ per cycle. A 2 g mosquito flying at 1 m/s has kinetic energy ½ × 0.002 × 1² = 1 mJ. Electrocautery monopolar pulses deliver 50-500 mJ to coagulate blood vessels. 1 mJ = 10⁻³ J = 0.2390 cal.

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