Volts to Joules Calculator
Convert electric potential in volts (V) to energy in joules (J). Enter the voltage in volts and the charge in coulombs, then press Calculate — the energy result appears in joules, multiplied straight from E = V × Q. Everything runs locally in your browser.
Enter volts
Type the voltage V in volts (V) — the electric potential difference across which the charge moves. Zero volts is fine and gives 0 J.
Enter coulombs
Type the electrical charge Q in coulombs (C). Any finite number works — zero included — because the energy simply multiplies voltage by charge.
Press Calculate, read joules
The energy E appears in joules (J), shown to at most ten significant digits. Copy the result to your clipboard, or press Reset to clear everything and start over.
How volts become joules
- What is the volts-to-joules formula?
- The energy E in joules (J) is equal to the voltage V in volts (V), times the electrical charge Q in coulombs (C): E(J) = V(V) × Q(C). One joule is the energy released when one coulomb of charge moves through a potential difference of one volt.
- Worked example
- If a charge of 3 C moves through a potential difference of 12 V, the energy is E = 12 V × 3 C = 36 J. Likewise 9 V across 0.25 C gives 9 × 0.25 = 2.25 J.
- Is zero allowed?
- Yes. Because E = V × Q is a multiplication, zero on either operand is perfectly valid: 0 V × 7 C = 0 J and 12 V × 0 C = 0 J. There is no division, so there is no undefined case — a real 0 V or 0 C just means no energy is transferred.
- What about negative values?
- The arithmetic is defined for negative voltage or negative charge (E = −12 V × 3 C = −36 J), which corresponds to energy released in the opposite direction of the assumed charge flow. Two negatives multiply to a positive. Both compute here rather than being rejected.
- How accurate is the result?
- Results are computed in standard double-precision arithmetic and displayed with at most ten significant digits with floating-point noise trimmed, so 1.1 × 3 shows as exactly 3.3. If a product overflows the number range (e.g. 1e308 × 10), the calculator reports that the result is too large to display instead of printing Infinity.
Privacy: every calculation runs in your browser tab — no value you type is sent anywhere. Copy result uses your clipboard only. Results are ideal circuit-theory figures; verify real installations with a multimeter.