Joules to Volts Calculator
Convert energy in Joules to potential difference in Volts and Volts to Joules quickly with our dual-purpose electrical calculator. Support calculations using electric charge in Coulombs.
Joules to Volts Calculator
How to Use the Joules to Volts Calculator
Follow these simple steps to convert electrical energy in Joules (J) to potential difference in Volts (V):
- 1Enter Energy: Input the energy value in Joules (J) in the first input box.
- 2Enter Charge: Input the electric charge quantity in Coulombs (C) in the second input box.
- 3Calculate: Click the Calculate to Volts button to perform the sizing calculation.
How to Calculate Joules to Volts (Sizing Guide)
To convert energy in Joules (J) to electric potential difference in Volts (V), you must know the electric charge quantity in Coulombs (C). Because voltage represents the ratio of potential energy per unit charge, a direct conversion is impossible without knowing the charge constant of the system.
Real-Life Joules to Volts Sizing Scenarios
Scenario 1: DC Motor Test on a Battery
A DC motor test run delivers 4,320 Joules of energy to the motor while 360 Coulombs of charge flow through it (3 A for 120 seconds). The supply potential in Volts is:
Volts = 4,320 Joules ÷ 360 Coulombs = 12 Volts
Scenario 2: USB Charging Port
A USB port delivers 300 Joules to a phone while 60 Coulombs of charge flow (1 A for 60 seconds). The port voltage is calculated as:
Volts = 300 Joules ÷ 60 Coulombs = 5 Volts
Step-by-Step Sizing Guide & Formulas
Voltage (V) = Energy (Joules) ÷ Charge (Coulombs)
Note for capacitors: V = E ÷ Q assumes the charge moves through a constant potential difference. A capacitor discharging from voltage V to zero releases E = ½ × Q × V, so its starting voltage is V = 2 × E ÷ Q.
Step 1: Identify given inputs. Assume a system stores 120 Joules of energy and carries a charge of 1 Coulomb.
Step 2: Apply the formula by dividing the energy value by the charge value:
120 Joules ÷ 1 Coulomb = 120 Volts
Final Answer: The potential difference is 120 Volts.
Joules to Volts Conversion Table
The reference table below outlines equivalent voltages for various energy levels, assuming a fixed electric charge of 1.0 Coulomb:
| Energy (Joules) | Charge (Coulombs) | Potential difference (Volts) |
|---|---|---|
| 1 J | 1.0 C | 1 V |
| 5 J | 1.0 C | 5 V |
| 10 J | 1.0 C | 10 V |
| 20 J | 1.0 C | 20 V |
| 50 J | 1.0 C | 50 V |
| 100 J | 1.0 C | 100 V |
| 120 J | 1.0 C | 120 V |
| 200 J | 1.0 C | 200 V |
| 300 J | 1.0 C | 300 V |
| 360 J | 1.0 C | 360 V |
| 500 J | 1.0 C | 500 V |
200 joules to volts
A rating of 200 Joules is common in mid-tier emergency defibrillators or industrial laboratory pulse testers. Sizing voltage requirements:
- Formula:
Volts = 200 Joules ÷ Charge - For a 1.0 Coulomb charge: Sizing voltage yields
200 ÷ 1 = 200 Volts. - For a 10.0 Coulomb charge: Sizing voltage yields
200 ÷ 10 = 20 Volts.
360 joules to volts
360 Joules is the standard maximum energy setting for monophasic external defibrillators (biphasic units typically deliver 120 to 200 Joules, with some up to 360 Joules). Sizing output potential:
- Formula:
Volts = 360 Joules ÷ Charge - For a 0.2 Coulomb discharge: Sizing voltage yields
360 ÷ 0.2 = 1,800 Volts. - For a 2.0 Coulomb discharge: Sizing voltage yields
360 ÷ 2 = 180 Volts.
300 joules to volts
300 Joules of kinetic work represents a standard potential energy storage target for small pulse welding capacitors or laboratory test circuits.
- Formula:
Volts = 300 Joules ÷ Charge - For a 1.5 Coulomb charge: Sizing voltage yields
300 ÷ 1.5 = 200 Volts. - For a 5.0 Coulomb charge: Sizing voltage yields
300 ÷ 5 = 60 Volts.
150 joules to volts
150 Joules of stored energy corresponds to low-energy medical cardiac shock protocols or heavy-duty photo studio flash networks.
- Formula:
Volts = 150 Joules ÷ Charge - For a 1.25 Coulomb charge: Sizing voltage yields
150 ÷ 1.25 = 120 Volts. - For a 3.0 Coulomb charge: Sizing voltage yields
150 ÷ 3 = 50 Volts.
120 joules to volts
120 Joules of energy represents a standard potential difference evaluation threshold for split-phase appliances or small solar chargers.
- Formula:
Volts = 120 Joules ÷ Charge - For a 1.0 Coulomb charge: Sizing voltage yields
120 ÷ 1 = 120 Volts. - For a 2.0 Coulomb charge: Sizing voltage yields
120 ÷ 2 = 60 Volts.
100 joules to volts
A round rating of 100 Joules is common for high-capacity electronics laboratories, electrostatic pulse testers, and low-energy capacitors.
- Formula:
Volts = 100 Joules ÷ Charge - For a 5.0 Coulomb charge: Sizing voltage yields
100 ÷ 5 = 20 Volts. - For a 10.0 Coulomb charge: Sizing voltage yields
100 ÷ 10 = 10 Volts.
1 joules to volts
1 Joule of energy equals exactly 1 Volt when acting upon a charge quantity of 1 Coulomb. This standard SI definition scales as follows:
- Formula:
Volts = 1 Joule ÷ Charge - For a 1.0 milli-Coulomb charge (0.001C): Sizing voltage yields
1 ÷ 0.001 = 1,000 Volts. - For a 0.5 Coulomb charge: Sizing voltage yields
1 ÷ 0.5 = 2 Volts.
.15 joules to volts
A small energy level of 0.15 Joules (150 mJ) is typical of small capacitor discharges and ignition test circuits. For comparison, a human static electricity shock is usually only a few millijoules.
- Formula:
Volts = 0.15 Joules ÷ Charge - For a 1.0 micro-Coulomb charge (1e-6 C): Sizing voltage yields
0.15 ÷ 1e-6 = 150,000 Volts(high static voltage potential). - For a 1.0 milli-Coulomb charge (0.001 C): Sizing voltage yields
0.15 ÷ 0.001 = 150 Volts.
Frequently Asked Questions (FAQs)
No. Joules measure energy and work, while Volts measure potential difference. 1 Joule equals 1 Volt only if the charge quantity is exactly 1 Coulomb (1 V = 1 J ÷ 1 C).
To convert energy in Joules (J) to potential difference in Volts (V), divide the energy by the electric charge in Coulombs (C): V = J ÷ C.
200 Joules represents a very small energy quantity, equal to 200 Watt-seconds, or approximately 0.056 Watt-hours (Wh). It is enough to power a 10W light bulb for 20 seconds.
300 Joules represents 300 Watt-seconds, or approximately 0.083 Wh. This represents the energy consumed by a 1-Watt device operating for 5 minutes.
In electrical circuits, 1 Joule represents exactly 1 Watt-second. It is defined as the work done by a current flow of 1 Ampere through a resistance of 1 Ohm for a duration of exactly 1 second.
One Joule is equal to approximately 6.2415 × 10^(18) electron Volts (eV).
