Convert Attojoules to Millijoules

Convert Attojoules (aJ) to Millijoules (mJ) instantly and accurately.

Attojoules (aJ)
Millijoules (mJ)

Conversion Formula

mJ = aJ × 1.000000000e-15

About Attojoules

An attojoule (aJ) is 10⁻¹⁸ J - the scale of individual X-ray photons and superconducting qubit circuits. A 1 keV X-ray photon carries 160 aJ; a visible green photon (~550 nm) carries ~0.36 aJ. Josephson junction energies in superconducting qubits are set in tens to hundreds of aJ to achieve quantum coherence at millikelvin temperatures. XRISM's cryogenic TES X-ray spectrometer resolves individual photon energies at the hundreds-of-aJ level with ~7 eV FWHM resolution. 1 aJ = 10⁻¹⁸ J = 6.242 eV.

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.

Quick Reference Table

Attojoules (aJ)Millijoules (mJ)
1 aJ1 × 10-15 mJ
2 aJ2 × 10-15 mJ
5 aJ5 × 10-15 mJ
10 aJ1 × 10-14 mJ
25 aJ2.5 × 10-14 mJ
50 aJ5 × 10-14 mJ
100 aJ1 × 10-13 mJ

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