What Is a Free Watts to Volts Calculator?
A Free Watts to Volts Calculator (W to V Calculator) is an online electrical calculation tool used to determine voltage in volts (V) when you know the power in watts (W) and the current in amperes (A).
It is useful for electricians, electrical engineers, technicians, electronics hobbyists, solar installers, and anyone working with electrical circuits and power systems.
Watts to Volts Formula
For a DC circuit, the formula is:
Volts = Watts ÷ Amps
or:
V = W ÷ A
For example, if a device uses 600 watts and draws 5 amps:
V = 600 ÷ 5
V = 120 V
Therefore, the voltage is 120 volts.
Single-Phase AC Formula
For a single-phase AC circuit, if power factor is known:
Volts = Watts ÷ (Amps × Power Factor)
For example:
- Power = 1,920 W
- Current = 10 A
- Power factor = 0.80
V = 1,920 ÷ (10 × 0.80)
V = 240 V
Three-Phase AC
For a balanced three-phase system, if calculating line voltage from total real power and line current:
V = Watts ÷ (√3 × Amps × Power Factor)
where √3 ≈ 1.732.
Quick Watts to Volts Examples
| Power | Current | Voltage* |
|---|---|---|
| 60 W | 5 A | 12 V |
| 120 W | 10 A | 12 V |
| 240 W | 10 A | 24 V |
| 600 W | 5 A | 120 V |
| 1,200 W | 10 A | 120 V |
| 2,400 W | 10 A | 240 V |
*Examples assume DC or a power factor of 1.0.
Why Use a Free Watts to Volts Calculator?
A Free Watts to Volts Calculator can help you:
- Calculate voltage from power and current
- Analyze electrical circuits
- Check power-supply specifications
- Work with batteries and DC systems
- Estimate solar-system voltage
- Troubleshoot electrical equipment
- Understand appliance electrical ratings
- Perform electrical engineering calculations
Important: Watts Alone Cannot Determine Volts
You cannot convert watts to volts using watts alone. Current must also be known.
The fundamental relationship is:
Watts = Volts × Amps
Therefore:
Volts = Watts ÷ Amps
For AC systems, the power factor and phase configuration may also need to be considered.
Example: Solar System
Suppose a solar device produces 1,000 W while operating at 50 A:
V = 1,000 ÷ 50
V = 20 V
So the operating voltage is 20 volts, assuming a DC system.
In Short
A Free Watts to Volts Calculator makes it easy to calculate voltage when power and current are known.
Basic formula:
V = W ÷ A
For example, 1,200 watts ÷ 10 amps = 120 volts.
For AC applications, use the appropriate formula that accounts for power factor and, when applicable, three-phase power.
