Energy Converters
Convert between energy units: joules, kilojoules, calories, kilocalories, electron volts, kWh, and BTU. Used in thermochemistry, calorimetry, and spectroscopy.
Energy appears throughout chemistry — bond energies, reaction enthalpies, activation energies, ionization energies, and photon energies all require fluency with different energy units. The SI unit is the joule, but chemists regularly encounter calories (from calorimetry), electron volts (from spectroscopy and atomic physics), and kilojoules per mole (for reaction thermodynamics).
61 Energy Conversions
BTU to Calories Converter
cal = BTU × 252.164
1 BTU works out to 252.164 thermochemical calories. The factor lives at the seam between US combustion-engineering heat data and calorie-scale chemistry calorimetry — about 4 BTU to a kcal as a useful mental anchor.
BTU to Joules Converter
J = BTU × 1055.06
Convert British Thermal Units to joules by multiplying by 1055.06. The step that brings US industrial heating and combustion data into SI.
BTU to Kilojoules Converter
kJ = BTU × 1.05506
1 BTU = 1.05506 kJ. Close enough that '1 BTU ≈ 1 kJ' works as a rough check (off by 5.5%), but the full factor is the one that lets US-tradition boiler ratings and fuel heating values land alongside chemistry thermodynamics in kJ.
BTU to Kilowatt-hours Converter
kWh = BTU × 0.000293071
Convert BTU to kilowatt-hours by multiplying by 2.93071 × 10⁻⁴. Useful any time US thermal-fuel energy and the kWh form an electrical-energy bill reads in have to agree.
BTU to Megajoules Converter
MJ = BTU × 0.00105506
Convert BTU to megajoules by multiplying by 0.00105506. A unit step between US-tradition heating values and the MJ units fuel-content reporting uses internationally.
BTU to Watt-hours Converter
Wh = BTU × 0.293071
Convert BTU to watt-hours by multiplying by 0.293071. Used at the handoff between US thermal-load specs and the Wh form a battery-budget calculation reads in.
Calories to BTU Converter
BTU = cal × 0.003966
1 thermochemical calorie = 0.003966 BTU. About 252 cal to a BTU as a useful mental anchor. The factor lands chemistry-side calorimetry results in the BTU form US engineering specs default to.
Calories to Electronvolts Converter
eV = cal × 2.6114 × 10¹⁹
1 cal = 2.6114 × 10¹⁹ eV — but that's almost never the form you actually want. The per-mole version (1 kcal/mol = 0.04336 eV/particle) is what shows up when an old thermochemistry table needs to be compared against a DFT calculation.
Calories to Joules Converter
J = cal × 4.184
Convert calories to joules using the exact factor 1 cal = 4.184 J. The step that makes older thermochemistry data usable in SI-based calculations.
Calories to Joules Converter (Thermochemical)
J = cal × 4.184
Convert thermochemical calories to joules by multiplying by 4.184. The exact factor that bridges legacy calorie-based thermodynamic data to modern SI energy units.
Calories to Kilocalories Converter
kcal = cal / 1000
Divide calories by 1000. That single decimal shift separates the small calorie of physical chemistry from the dietary Calorie of nutrition labels — and it's responsible for more thermochemistry errors than any other unit confusion in chemistry.
Calories to Kilojoules Converter
kJ = cal × 0.004184
Convert calories to kilojoules by multiplying by 0.004184. The exact factor that takes a calorie-based reaction or food-energy value into the kJ units modern chemistry uses.
Calories to Kilowatt-hours Converter
kWh = cal × 1.16222 × 10⁻⁶
One thermochemical calorie equals 1.162 × 10⁻⁶ kWh. Tiny number, predictable shape — six prefix decades stand between calorimetric heat output and the kWh column on an electricity bill, and that's exactly the gap the conversion crosses.
Electronvolts to Calories Converter
cal = eV × 3.8293 × 10⁻²⁰
Convert electronvolts to thermochemical calories by multiplying by 3.8293 × 10⁻²⁰. Useful any time per-particle atomic-physics energies into per-particle thermochemistry units have to agree.
Electronvolts to Joules Converter
J = eV × 1.60218 × 10⁻¹⁹
Convert electronvolts to joules using 1 eV = 1.602 × 10⁻¹⁹ J. The conversion for dropping spectroscopic, photochemical, or atomic-scale energies into an SI calculation.
Electronvolts to Kilocalories per Mole Converter
kcal/mol = eV × 23.0605
Convert eV per particle to kcal/mol by multiplying by 23.0605. Comes up at the boundary of per-particle quantum-chemistry output into the per-mole form thermochemistry tables read in.
Electronvolts to Kilojoules Converter
kJ = eV × 1.60218 × 10⁻²²
Convert electronvolts to kilojoules by multiplying by 1.60218 × 10⁻²². Used at the handoff between single-particle energies and the per-mole values bulk thermochemistry uses.
Electronvolts to kJ/mol Converter
kJ/mol = eV × 96.485
Convert eV per particle to kJ/mol by multiplying by 96.485. A unit step between per-particle quantum-chemistry energies into the per-mole form a thermodynamic table reads in.
Electronvolts to Watt-hours Converter
Wh = eV × 4.4505 × 10⁻²³
Convert electronvolts to watt-hours by multiplying by 4.4505 × 10⁻²³. Comes up at the boundary of atomic-scale energies and practical electrical energy units.
Gigahertz to Hertz Converter
Hz = GHz × 1000000000
Convert gigahertz to hertz by multiplying by 10⁹. The factor of a billion between microwave-spectroscopy publication units and the raw Hz frequencies an instrument actually samples.
Hertz to Gigahertz Converter
GHz = Hz ÷ 1000000000
Convert hertz to gigahertz by dividing by 10⁹. The nine-decade prefix step that brings a frequency-counter reading into the GHz form microwave spectroscopy uses.
Hertz to Kilohertz Converter
kHz = Hz / 1000
Divide hertz by 1000 to get kilohertz. A trivial prefix shift, but the one that bridges raw transducer readings (Hz) and the kHz numbers labeled on ultrasonic horns, electrochemical impedance sweeps, and most audio-range chemistry equipment.
Hertz to Megahertz Converter
MHz = Hz / 1000000
Convert hertz to megahertz by dividing by 10⁶. The everyday step in NMR spectroscopy between absolute peak frequencies in Hz and the MHz spectrometer-frequency anchor.
Hertz to Terahertz Converter
THz = Hz × 10⁻¹² (equivalently, THz = Hz ÷ 10¹²)
Convert hertz to terahertz by dividing by 10¹². The twelve-decade prefix step that takes raw frequency-counter Hz into the THz scale far-IR spectroscopy uses.
Joules to BTU Converter
BTU = J × 0.000947817
Convert joules to British thermal units by multiplying by 0.000947817. The step between SI reaction energetics and the BTU units US process-heat and HVAC calculations run in.
Joules to Calories Converter
cal = J ÷ 4.184
Divide by 4.184 — exactly. The factor was pinned to that value in 1956 specifically so the conversion would never have to round.
Joules to Electronvolts Converter
eV = J ÷ 1.602176634 × 10⁻¹⁹
Convert joules to electronvolts by dividing by 1.602 × 10⁻¹⁹. The translation from macroscopic energy units into the per-particle scale where atomic and molecular physics naturally live.
Joules to Kilocalories Converter
kcal = J / 4184 (equivalently, kcal = J × 2.39 × 10⁻⁴)
Convert joules to kilocalories by dividing by 4184. The exact factor that bridges modern SI energy values to the kcal/mol units biochemistry and older physical-chemistry references use.
Joules to Kilojoules Converter
kJ = J ÷ 1000
Convert joules to kilojoules by dividing by 1000. The step that turns raw calorimeter output into numbers that match textbook enthalpy tables.
Joules to Kilowatt-Hours Converter
kWh = J / 3,600,000
Convert joules to kilowatt-hours by dividing by 3.6 × 10⁶. A unit step between laboratory-scale energy and the kWh unit electrical bills and industrial process calculations use.
Joules to Megajoules Converter
MJ = J × 10⁻⁶
Convert joules to megajoules by dividing by 10⁶. The factor that takes reaction-scale energies up to the MJ values used for fuel content and explosion analysis.
Joules to Watt-hours Converter
Wh = J / 3600
Convert joules to watt-hours by dividing by 3600. Useful any time SI energy values and the Wh units electrochemistry and battery work use have to agree.
Kilocalories per Mole to Electronvolts Converter
eV = kcal/mol × 0.043364
Convert kcal/mol to eV per particle by multiplying by 0.043364. Used at the handoff between per-mole thermochemistry into the per-particle electron-energy units physics and DFT use.
Kilocalories to Calories Converter
cal = kcal × 1000
Convert kcal to cal by multiplying by 1000. The factor is the kilo prefix, but the conversion is the routine fix for the small-cal vs. food-Calorie confusion that keeps showing up in nutrition data.
Kilocalories to Joules Converter
J = kcal × 4184
Convert kilocalories to joules by multiplying by 4184. The exact factor that takes a kcal/mol value from older biochemistry references into the SI joule units modern simulations and calculations expect.
Kilocalories to Kilojoules Converter
kJ = kcal × 4.184
Convert kilocalories to kilojoules by multiplying by 4.184. The exact bridge between calorie-based reaction energetics in older biochemistry texts and the SI kJ values modern data uses.
Kilocalories to Kilowatt-hours Converter
kWh = kcal × 0.001162
Convert kcal to kWh by multiplying by 1.162 × 10⁻³. A unit step between calorimetric or food-energy data and the kWh form an electrical-energy ledger uses.
Kilohertz to Hertz Converter
Hz = kHz × 1000
Convert kHz to Hz by multiplying by 1000. The kilo prefix step that brings instrument-spec kHz frequencies into the Hz form NMR coupling constants and Sauerbrey-equation calculations use.
Kilojoules to BTU Converter
BTU = kJ × 0.947817
1 kJ = 0.947817 BTU. The bridge between SI process-heater duty figures and the BTU-based heat-exchanger documentation US refineries write in. Roughly speaking: 1 kJ is just under a BTU, off by 5.5%.
Kilojoules to Calories Converter
cal = kJ × 239.006
Convert kJ to thermochemical calories by multiplying by 239.006. A unit step between modern SI energy data into the calorie scale older thermochemistry references use.
Kilojoules to Electronvolts Converter
eV = kJ × 6.242 × 10²¹
Multiply by 6.242 × 10²¹ for total electronvolts. The per-mole version — divide kJ/mol by 96.485 — is the one that actually comes up in practice.
Kilojoules to Joules Converter
J = kJ × 1000
Convert kilojoules to joules by multiplying by 1000. The direction that takes a tabulated reaction enthalpy into SI base units, ready for the Arrhenius equation or detailed kinetic modeling.
Kilojoules to Kilocalories Converter
kcal = kJ / 4.184
Convert kilojoules to kilocalories by dividing by 4.184. The step between SI reaction enthalpies and the kcal/mol that still dominates biochemistry and older physical-chemistry references.
Kilojoules to Kilowatt-hours Converter
kWh = kJ ÷ 3600
Convert kJ to kWh by dividing by 3600. Exact, since 1 kWh = 1 kW × 3600 s = 3.6 × 10⁶ J.
Kilojoules to Megajoules Converter
MJ = kJ ÷ 1000
Convert kJ to MJ by dividing by 1000. The decimal step that aggregates per-stream reaction energies into the plant-scale figures pinch analysis runs in.
Kilojoules to Watt-hours Converter
Wh = kJ × 0.27778
Convert kJ to watt-hours by dividing by 3.6. Exact, since 1 Wh = 1 W × 3600 s = 3600 J.
Kilowatt-hours to BTU Converter
BTU = kWh × 3412.14
1 kWh = 3412.14 BTU, exact through 1 kWh = 3.6 × 10⁶ J and 1 BTU = 1055.06 J. The bridge from electricity-meter readings into the BTU form US thermal-load specs assume.
Kilowatt-hours to Calories Converter
cal = kWh × 860421
Convert kWh to thermochemical calories by multiplying by 860,421. Useful any time electrical-energy meter readings into the calorie scale calorimetric data uses have to agree.
Kilowatt-hours to Joules Converter
J = kWh × 3600000
Convert kilowatt-hours to joules by multiplying by 3,600,000. The step that turns an electricity-meter reading into the SI energy unit chemistry calculations expect.
Kilowatt-hours to Kilocalories Converter
kcal = kWh × 860.421
1 kWh = 860.421 kcal. The bridge from electricity-meter readings into the kcal scale used by combustion chemistry, calorimetric references, and any food-energy comparison.
Kilowatt-hours to Kilojoules Converter
kJ = kWh × 3600
Convert kWh to kJ by multiplying by 3600. The factor follows directly from 1 kWh = 1 kW × 3600 s.
kJ/mol to Electronvolts Converter
eV = kJ/mol × 0.010364
Convert kJ/mol to eV per particle by multiplying by 0.010364. Comes up at the boundary of per-mole thermochemistry into the per-particle electronvolt scale physics and surface chemistry use.
Megahertz to Hertz Converter
Hz = MHz × 1000000
NMR spectrometers wear MHz nameplates (400 MHz, 600 MHz, 900 MHz). Their probe-tuning, network-analyzer outputs, and chemical-shift offsets all live in raw Hz. The factor of 10⁶ reconciles the two views.
Megajoules to BTU Converter
BTU = MJ × 947.817
Convert MJ to BTU by multiplying by 947.817. Useful any time SI gas-calorimetry data into the BTU form US heating-value documentation reads in have to agree.
Megajoules to Joules Converter
J = MJ × 10⁶
Convert megajoules to joules by multiplying by 10⁶. Six prefix decades sit between bulk-fuel energy data and the joule-scale arithmetic SI equations expect.
Megajoules to Kilojoules Converter
kJ = MJ × 1000
Convert MJ to kJ by multiplying by 1000. The decimal step that breaks plant-scale energy summaries down into the per-stream form heat-exchanger calculations use.
Terahertz to Hertz Converter
Hz = THz × 10¹²
Convert terahertz to hertz by multiplying by 10¹². The 12-decade prefix step bridging far-infrared spectroscopy and base-SI frequency.
Watt-hours to BTU Converter
BTU = Wh × 3.41214
Convert watt-hours to BTU by multiplying by 3.41214. Comes up when electrical-energy ratings must be expressed in the BTU form HVAC heat-load calculations read.
Watt-hours to Electronvolts Converter
eV = Wh × 2.247 × 10²²
Multiply watt-hours by 2.247 × 10²² to land in electronvolts. Twenty-two decades of separation, which is just what you'd expect when bridging a macroscopic battery to atomic-scale per-electron units.
Watt-hours to Joules Converter
J = Wh × 3600
Convert watt-hours to joules by multiplying by 3600. Exact by definition: 1 W = 1 J/s and 1 hour = 3600 s.
Watt-hours to Kilojoules Converter
kJ = Wh × 3.6
Convert watt-hours to kilojoules by multiplying by 3.6. Exact by definition: 1 Wh = 3600 J = 3.6 kJ.