Find voltage from amps using resistance or power. Handle DC, AC, and quick comparison cases. Use clean inputs, exports, formulas, and examples with confidence.
| Method | Current | Resistance | Power | PF | Voltage Output |
|---|---|---|---|---|---|
| Current and Resistance | 5 A | 24 Ω | 120 W | Not used | 120 V |
| Power and Current | 15 A | Not used | 1800 W | Not used | 120 V |
| Single-Phase AC | 10 A | Not used | 2300 W | 1.00 | 230 V |
| Three-Phase AC | 25 A | Not used | 15000 W | 0.80 | 433.01 V |
V = I × R
Use this when circuit current and resistance are known.
V = P ÷ I
Use this when electrical power and current are available.
V = P ÷ (I × PF)
Use this for real power in single-phase systems.
V = P ÷ (√3 × I × PF)
Returns balanced line-to-line voltage in three-phase circuits.
All inputs are converted into base units before calculation. That keeps the result consistent across A, mA, kA, W, kW, MW, Ω, kΩ, and MΩ selections.
Not by current alone. You also need resistance, power, or circuit power factor. Voltage depends on the relationship between current and other electrical values.
Use V = I × R when resistance is known. Use V = P ÷ I for DC power cases. Use the AC formulas when power factor affects the circuit.
Power factor is the ratio between real power and apparent power. It matters in AC systems because it changes the voltage estimate for the same current and power.
No. The three-phase formula here returns balanced line-to-line voltage. That is the most common requirement for practical three-phase electrical calculations.
Yes. The calculator converts selected units into base units automatically. That helps you work with small electronics and larger industrial systems on one page.
A required value may be missing or zero. Check current first, then confirm the selected method has all needed fields filled correctly.
The CSV file stores the method, formula, converted inputs, voltage output, working line, and note. It is useful for project records and quick spreadsheet review.
It is suitable for estimation and verification. Final design decisions should also consider system standards, temperature effects, harmonics, cable losses, and safety margins.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.