Watts to Electron Volts Calculator
Convert electrical power in watts to energy in electron volts and back. Bidirectional converter with time input and simultaneous output in eV, keV, MeV, GeV, and TeV—features no other online calculator provides.
How to Use the Watts to Electron Volts Calculator
This is the only online calculator that provides bidirectional watts ↔ eV conversion with adjustable time units and simultaneous multi-scale output. Competitors either lack the time input entirely or show results in only one unit—our tool shows eV, keV, MeV, GeV, and TeV simultaneously.
Choose Direction
Select "Watts → eV" to convert power to energy, or "eV → Watts" for the reverse conversion.
Enter Values with Units
Input power in μW to MW, time in μs to days. Or enter energy in eV to TeV. Unit dropdowns handle all conversions automatically.
Read All Scales at Once
Results appear in all five eV scales (eV, keV, MeV, GeV, TeV) plus joules and the eV/s rate simultaneously.
Watts to Electron Volts Formula
Example Calculations
Also = 6.2415 PeV (petaelectronvolts)
That's 1.348 YeV (yottaelectronvolts)—enough energy to accelerate 10¹¹ LHC protons.
A milliwatt laser pulse lasting 1 microsecond delivers energy equivalent to a few proton rest masses.
About 1,872 EeV (exaelectronvolts). More energy than any cosmic ray ever detected.
One kilowatt-hour = 22.47 septillion electron volts. This is the unit on your electricity bill.
Watts to Electron Volts Conversion Table
| Power × Time | Joules | Electron Volts | Best Unit |
|---|---|---|---|
| 1 μW·μs | 10⁻¹² J | 6.24 × 10⁶ | 6.24 MeV |
| 1 mW·ms | 10⁻⁶ J | 6.24 × 10¹² | 6.24 TeV |
| 1 mW·s | 10⁻³ J | 6.24 × 10¹⁵ | 6,242 TeV |
| 1 W·s | 1 J | 6.24 × 10¹⁸ | 6.24 EeV |
| 1 W·min | 60 J | 3.74 × 10²⁰ | 374 EeV |
| 1 W·hr | 3,600 J | 2.25 × 10²² | 22.5 ZeV |
| 1 kW·hr | 3.6 × 10⁶ J | 2.25 × 10²⁵ | 22,500 YeV |
Real-World Energy in Electron Volts
Electron volts span an incredible range—from the thermal energy of room-temperature atoms to the cosmic rays that bombard Earth from deep space. This table puts different energy scales in perspective.
| Phenomenon | Energy | In eV |
|---|---|---|
| Room temp thermal energy | ~4 × 10⁻²¹ J | 0.025 eV |
| Red light photon (700nm) | 2.84 × 10⁻¹⁹ J | 1.77 eV |
| Green light photon (550nm) | 3.61 × 10⁻¹⁹ J | 2.25 eV |
| UV photon (250nm) | 7.95 × 10⁻¹⁹ J | 4.96 eV |
| Dental X-ray photon | ~1.1 × 10⁻¹⁵ J | ~70 keV |
| Alpha particle decay | ~8 × 10⁻¹³ J | ~5 MeV |
| Proton rest mass (E=mc²) | 1.503 × 10⁻¹⁰ J | 938.27 MeV |
| LHC proton beam (per proton) | 1.04 × 10⁻⁶ J | 6.5 TeV |
| Highest cosmic ray detected ("Oh-My-God") | 51 J | 3.2 × 10²⁰ eV |
| 1 kilowatt-hour | 3.6 × 10⁶ J | 2.25 × 10²⁵ eV |
Understanding Watts and Electron Volts
The conversion between watts and electron volts bridges two different physical concepts: power (the rate of energy transfer) and energy (the total amount of work). This distinction is crucial in fields ranging from electrical engineering to particle physics, and understanding it deeply separates experts from beginners.
Why Can't You Convert Watts to eV Directly?
Watts measure power—energy per unit time (joules per second). Electron volts measure energy—the total amount. Converting between them requires a time component, just like converting speed (km/h) to distance (km) requires knowing how long you traveled. Our calculator is the only online tool that handles this correctly by accepting both power and time as inputs. Other "converters" online either show only the rate (eV/s per watt) or incorrectly equate watts and eV, which is like saying "60 mph equals 60 miles"—dimensionally wrong.
The Electron Volt in Modern Physics
The electron volt was first proposed by researchers working on cathode ray tubes in the early 1900s. It became indispensable as quantum mechanics and nuclear physics revealed that atomic-scale energies are incredibly small in joules. Using eV simplifies the numbers: a hydrogen atom's ionization energy is 13.6 eV (vs. 2.18 × 10⁻¹⁸ J), and the proton mass is 938.27 MeV/c² (vs. 1.673 × 10⁻²⁷ kg).
Since the 2019 redefinition of SI units, the elementary charge (and thus the electron volt) is defined exactly: 1 eV = 1.602176634 × 10⁻¹⁹ J. This means the conversion constant used in this calculator is exact by definition—there is zero uncertainty in the conversion factor.
For calculations involving the enormous numbers from these conversions, try our Big Number Calculator for arbitrary-precision integer arithmetic. For related electrical conversions, use our Watts to Volts Calculator, Watts to Amps Calculator, or our AC Wattage Calculator to break down real power, apparent power, and reactive power for AC circuits.