Amps to Volts: Formula, Calculator & Conversion Chart

You cannot directly convert amps to volts because amperes measure electrical current while volts measure electrical potential difference. To calculate voltage from amps, you need at least one additional value—usually power in watts or resistance in ohms. For AC systems, you may also need power factor and phase information.

The two most common amps-to-volts formulas are:

Using power:

Voltage (V) = Power (W) ÷ Current (A)

Using resistance:

Voltage (V) = Current (A) × Resistance (Ω)

For example, if a DC load consumes 1,200W while drawing 10A:

1,200W ÷ 10A = 120V

If instead 10A flows through a 12Ω resistive load:

10A × 12Ω = 120V

You can use an Amps to Volts Calculator to calculate the result.

Amps to Volts Conversion Table

Using Watts (Power)

Current (Amps)	Example Power	Calculation Formula	Voltage (Volts)
1 A	1000 W	1000 W ÷ 1 A	1000 V
2 A	1000 W	1000 W ÷ 2 A	500 V
3 A	1000 W	1000 W ÷ 3 A	333.33 V
4 A	1000 W	1000 W ÷ 4 A	250 V
5 A	1000 W	1000 W ÷ 5 A	200 V
6 A	1000 W	1000 W ÷ 6 A	166.67 V
8 A	1000 W	1000 W ÷ 8 A	125 V
10 A	1000 W	1000 W ÷ 10 A	100 V
12 A	1000 W	1000 W ÷ 12 A	83.33 V
13 A	1000 W	1000 W ÷ 13 A	76.92 V
15 A	1000 W	1000 W ÷ 15 A	66.67 V
16 A	1000 W	1000 W ÷ 16 A	62.50 V
20 A	1000 W	1000 W ÷ 20 A	50 V
25 A	1000 W	1000 W ÷ 25 A	40 V
30 A	1000 W	1000 W ÷ 30 A	33.33 V
40 A	1000 W	1000 W ÷ 40 A	25 V
50 A	1000 W	1000 W ÷ 50 A	20 V
60 A	1000 W	1000 W ÷ 60 A	16.67 V
80 A	1000 W	1000 W ÷ 80 A	12.50 V
100 A	1000 W	1000 W ÷ 100 A	10 V

Calculation Formula

Voltage (V) = Power (W) ÷ Current (A)

Example:
10 A at 1000 W = 1000 W ÷ 10 A = 100 V

AUsing Ohms (Resistance)

Current (Amps)	Example Resistance	Calculation	Voltage (Volts)
1 A	10 Ω	1 A × 10 Ω	10 V
2 A	10 Ω	2 A × 10 Ω	20 V
3 A	10 Ω	3 A × 10 Ω	30 V
4 A	10 Ω	4 A × 10 Ω	40 V
5 A	10 Ω	5 A × 10 Ω	50 V
6 A	10 Ω	6 A × 10 Ω	60 V
8 A	10 Ω	8 A × 10 Ω	80 V
10 A	10 Ω	10 A × 10 Ω	100 V
12 A	10 Ω	12 A × 10 Ω	120 V
13 A	10 Ω	13 A × 10 Ω	130 V
15 A	10 Ω	15 A × 10 Ω	150 V
16 A	10 Ω	16 A × 10 Ω	160 V
20 A	10 Ω	20 A × 10 Ω	200 V
25 A	10 Ω	25 A × 10 Ω	250 V
30 A	10 Ω	30 A × 10 Ω	300 V
40 A	10 Ω	40 A × 10 Ω	400 V
50 A	10 Ω	50 A × 10 Ω	500 V
60 A	10 Ω	60 A × 10 Ω	600 V
80 A	10 Ω	80 A × 10 Ω	800 V
100 A	10 Ω	100 A × 10 Ω	1000 V

Ohm's Law Formula

Voltage (V) = Current (A) × Resistance (Ω)

Example:
10 A × 10 Ω = 100 V

What Formula Converts Amps to Volts?

DC and resistive circuits can often use V=P/I or V=I×R, while AC calculations may require power factor and phase configuration.

Use this table before choosing a formula:

What You Know	Circuit	Formula for Voltage	Best Use
Amps + Watts	DC	V = P ÷ I	Batteries, DC loads
Amps + Ohms	Ohmic load	V = I × R	Resistors, simple circuits
Amps + Watts + PF	Single-phase AC	V = P ÷ (I × PF)	AC appliances, inverter output
Amps + Watts + PF	3-phase AC, line-to-line	V = P ÷ (√3 × I × PF)	Commercial/industrial systems
Amps + VA	Single-phase AC	V = VA ÷ I	Apparent-power calculations
Amps + VA	3-phase AC	V = VA ÷ (√3 × I)	3-phase apparent power

The basic relationships V = IR and P = VI are established electrical formulas. However, Ohm's Law should not be treated as a universal fixed-resistance model for every electronic device or nonlinear load.

This distinction becomes important with inverters, motors, LED drivers, switch-mode power supplies and other electronically controlled equipment.

For more background on power calculations, see Avepower’s power rating guide.

How Do You Convert Amps to Volts Using Watts?

When current and real electrical power are known in a DC circuit, calculate volts by dividing watts by amps: V=P÷I.

Formula

V = P ÷ I

Where:

• V = voltage in volts
• P = power in watts
• I = current in amps

Example: 1,200 Watts and 10 Amps

Known values:

P = 1,200W

I = 10A

Calculate:

V = 1,200 ÷ 10

V = 120V

Therefore, a 1,200W DC or unity-power-factor resistive load drawing 10A operates at 120V.

Example: 5,120 Watts and 100 Amps

5,120W ÷ 100A = 51.2V

This calculation is especially relevant to battery systems because 51.2V is a common nominal voltage for 16-cell LiFePO4 battery packs.

How Do You Convert Amps to Volts Using Ohms?

If current and resistance are known for an ohmic load, use Ohm's Law: voltage equals current multiplied by resistance.

Formula

V = I × R

Where:

• V = voltage
• I = current
• R = resistance

Example: 5 Amps Through 8 Ohms

5A × 8Ω = 40V

The voltage across the resistance is:

40V

Another Example

If 12A flows through a 10Ω resistance:

12A × 10Ω = 120V

According to Ohm's Law, the required voltage is 120V.

Why Does Higher Voltage Require Fewer Amps for the Same Power?

When power stays approximately constant, increasing voltage reduces the required current because I=P÷V.

Consider a 5,000W DC load before efficiency losses:

System Voltage	Approx. Current
12V	416.7A
24V	208.3A
48V	104.2A
51.2V	97.7A
100V	50A
400V	12.5A

The load is still 5kW.

What changes dramatically is current.

This is one reason residential energy storage commonly moves away from 12V architectures as power requirements increase.

Avepower explains this relationship further in its ampere and milliampere guide.

Can You Convert Amps to Volts Directly?

No. Amps and volts measure different electrical quantities, so there is no universal conversion such as “1 amp = X volts.” You must know another electrical value—typically watts, resistance, impedance, or other circuit information—before voltage can be calculated accurately.

An ampere measures electric current, while a volt measures electrical potential difference.

For a deeper explanation of this relationship, see Avepower’s voltage vs current guide and its introduction to what voltage means.

Amps vs Volts vs Watts vs Ohms

Quantity	Symbol	Unit	What It Measures
Voltage	V	Volt (V)	Electrical potential difference
Current	I	Ampere (A)	Rate of electric charge flow
Power	P	Watt (W)	Rate of electrical energy transfer
Resistance	R	Ohm (Ω)	Opposition to current flow

Conclusion

Amps cannot be directly converted to volts without additional electrical information. For DC systems, use V=P÷I when watts are known or V=I×R for an appropriate resistive load. For AC systems, confirm power factor and whether the circuit is single-phase or three-phase before calculating voltage.

Need Help Matching Battery Voltage, Current and Inverter Power?

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