1 cal_th | 4.184 J (joules) | 4.184×10^7 ergs (unit officially deprecated) | 0.001 Cal (dietary Calories) (unit officially deprecated) | 1000 mcal_th (thermochemical millicalories) (unit officially deprecated) | 0.001 kcal_th (thermochemical kilocalories) (unit officially deprecated) | 999.3 mcal_IT (millicalories (International Steam Table 1956)) (unit officially deprecated) | 0.9993 cal_IT (International Steam Table 1956 calories) (unit officially deprecated) | 998.6 mcal_mean (mean millicalories) (unit officially deprecated) | 0.9986 cal_mean (mean calories) (unit officially deprecated) | 1 cal_IUNS (IUNS calorie) (unit officially deprecated) | 0.003966 BTU_IT (IT British thermal units)

1 J | 0.239 cal_th 1 erg | 2.39×10^-8 cal_th 1 Cal | 1000 cal_th 1 mcal_th | 0.001 cal_th 1 kcal_th | 1000 cal_th 1 mcal_IT | 0.001001 cal_th 1 cal_IT | 1.001 cal_th 1 mcal_mean | 0.001001 cal_th 1 cal_mean | 1.001 cal_th 1 cal_IUNS | 0.9995 cal_th 1 BTU_IT | 252.2 cal_th

energy

amount of heat

kinetic energy

potential energy

mechanical energy

ionization energy

work

thermochemical millicalorie (mcal_th) | thermochemical kilocalorie (kcal_th)

(not in a named unit system)

officially deprecated (International Astronomical Union Style Manual. Comm. 5 in IAU Transactions XXB, 1989, Table 6)

unacceptable for use with SI (NIST Special Publication 1038, page 12, footnote 30 | NIST Special Publication 811, 2008 edition, Sec.5.3.2)

[mass] [length]^2 [time]^(-2)

Relativistic mass m from E = mc^2: | 47 fg (femtograms) | 4.7×10^-17 kg (kilograms)

Spectroscopic wavenumber for a photon from the Planck relation connecting spectroscopic wavenumber ν^~ with energy E = hcν^~: | 2.106×10^25 m^(-1) (reciprocal meters)

≈ 100 × estimated energy of most energetic neutrino ever detected (2025) ( ≈ 200 PeV )

≈ ( 0.04 ≈ 1/24 ) × approximate work done in moving 100 coulomb of charge between a potential difference of 1 volt ( ≈ 100 J )

≈ 4 × approximate work done in lifting a 100-gram apple vertically to a height of 1 meter ( ≈ 1 J )

≈ -8.7×10^(-6) × enthalpy change when two moles of gaseous hydrogen combine with one mole of gaseous oxygen to form two moles of water vapor ( -483.6 kJ )

≈ -5.1×10^(-6) × enthalpy of formation of one mole of aqueous sulfuric acid ( -814000 J )

≈ -3.7×10^(-6) × enthalpy of formation of one mole of solid sodium carbonate ( ≈ -1.13×10^6 J )