Volts to Amps & Amps to Volts Calculator

Use our dual-mode conversion calculator to easily switch between converting electrical voltage in Volts (V) to current in Amps (A) and current to voltage. Our tool offers instant, accurate calculations using power (Watts) or resistance (Ohms) parameters to assist in checking wiring capacities, breaker specifications, and circuit design.

By Nadeem Sial, Senior Electrical EngineerUpdated

Volts to Amps Calculator

V
W

How to Use the Volts to Amps Calculator

Follow these simple steps to convert electrical voltage in Volts (V) to current in Amps (A) using our online converter:

  1. 1
    Enter the input voltage in Volts (V).
  2. 2
    Choose the calculation basis (Watts-based power or Ohm's Law resistance).
  3. 3
    Enter the required active power in Watts (W) or circuit resistance in Ohms (Ω).
  4. 4
    Click the Calculate to Amps button to compute equivalent current.

How to Calculate Volts to Amps Manually

To convert voltage in Volts (V) to electrical current in Amperes (A), use either the power equation (dividing active power in Watts by voltage) or Ohm's Law (dividing voltage by circuit resistance). Sizing system current with these equations prevents overloading conductors and protects equipment.

Real-Life Scenarios

Scenario 1: Sizing circuit current for a residential water heater
A heavy residential electric water heater draws 4800 Watts of active power. Connected to a standard 240 Volts household line, sizing the current parameter yields:
Amps = 4800 Watts / 240 Volts = 20 Amps

Scenario 2: Sizing current for a low-voltage DC desktop charger
An automotive utility accessory charger draws 120 Watts of active power at 12 Volts. Sizing the actual current rating:
Amps = 120 Watts / 12 Volts = 10 Amps

Step-by-Step Calculation Guide

  1. 1
    Identify Parameters: Settle the system voltage and active power in Watts (or circuit resistance in Ohms).
  2. 2
    Select the Formula: Use Amps = Watts / Volts for power, or Amps = Volts / Resistance for Ohm's Law.
  3. 3
    Compute: Divide the values to obtain the active circuit current in Amperes.

Volts to Amps Conversion Chart

The chart below highlights conversion calculations from Volts to Amps across common residential and industrial load parameters:

Voltage (V) Active Power (W) Circuit Resistance (Ω) Resulting Current (A)
12 V60 W-5 A
12 V120 W-10 A
120 V60 W-0.5 A
120 V120 W-1 A
120 V600 W-5 A
120 V1,200 W-10 A
230 V230 W-1 A
230 V1,150 W-5 A
240 V2,400 W-10 A
240 V4,800 W-20 A

240 volts to amps

A standard industrial or high-power residential grid voltage of 240 Volts is commonly used for heavy appliances. Sizing calculations for electrical current yields:

  • For a 2400W Load (like a baseboard heater): drawing active power yields 2400 / 240 = 10 Amps.
  • For a 4800W Load (like a central water heater): drawing active power yields 4800 / 240 = 20 Amps.
  • For a circuit with 12-ohms of Resistance: current is sized using Ohm's Law as 240 / 12 = 20 Amps.

12 volts to amps

Sizing current on a low-voltage 12 Volt DC system (common in automotive electrical grids, marine systems, and LED drivers):

  • For a 120W Load (like a portable vacuum): drawing active power yields 120 / 12 = 10 Amps.
  • For a 24W Load (like a pair of LED worklights): drawing active power yields 24 / 12 = 2 Amps.
  • For a circuit with a 3-ohm Resistance: current is sized using Ohm's Law as 12 / 3 = 4 Amps.

watts and volts to amps

To convert Watts and Volts to Amps, apply the electric power equation: Amps = Watts / Volts. This formula determines the rate of electrical current flow (amperage) required to deliver a specified level of active power (wattage) at a given pressure (voltage). This conversion is fundamental for choosing proper wire gauges and circuit breaker sizing.

120 volts to amps

A standard North American domestic outlet potential of 120 Volts converts to current parameters:

  • For a 600W Appliance (like a blender): drawing active power yields 600 / 120 = 5 Amps.
  • For a 1200W Appliance (like a microwave oven): drawing active power yields 1200 / 120 = 10 Amps.
  • For a circuit with 15-ohms of Resistance: current is sized using Ohm's Law as 120 / 15 = 8 Amps.

230 volts to amps

For a standard European or international domestic socket rated at 230 Volts:

  • For a 2300W Load (like an electric kettle): drawing active power yields 2300 / 230 = 10 Amps.
  • For a 1150W Load (like a hairdryer on low): drawing active power yields 1150 / 230 = 5 Amps.
  • For a circuit with 46-ohms of Resistance: current is sized using Ohm's Law as 230 / 46 = 5 Amps.

220 volts to amps

A classic potential rating of 220 Volts (common in older systems or heavy machinery feeds) converts to:

  • For a 4400W Load (like a storage water heater): drawing active power yields 4400 / 220 = 20 Amps.
  • For a 2200W Load (like an oven heating element): drawing active power yields 2200 / 220 = 10 Amps.
  • For a circuit with 22-ohms of Resistance: current is sized using Ohm's Law as 220 / 22 = 10 Amps.

600 volts to amps

A high-voltage industrial distribution rating of 600 Volts converts to current parameters:

  • For a 30kW (30,000W) Resistive Heater Bank: drawing active power yields 30000 / 600 = 50 Amps.
  • For a circuit with a 60-ohm Resistance: current is sized using Ohm's Law as 600 / 60 = 10 Amps.

115 volts to amps

For utility grids rated at a nominal potential of 115 Volts:

  • For a 1150W Load (like a portable space heater): drawing active power yields 1150 / 115 = 10 Amps.
  • For a 575W Load (like a small rice cooker): drawing active power yields 575 / 115 = 5 Amps.
  • For a circuit with a 23-ohm Resistance: current is sized using Ohm's Law as 115 / 23 = 5 Amps.

250 volts to amps

A maximum terminal rating of 250 Volts (frequently specified for power receptacle limits and industrial plugs):

  • For a 5000W Load (like an electric furnace heating element): drawing active power yields 5000 / 250 = 20 Amps.
  • For a circuit with a 25-ohm Resistance: current is sized using Ohm's Law as 250 / 25 = 10 Amps.

FAQs About Converting Volts to Amps

No. They measure different dimensions. However, a 20 Amp current flow at 120 Volts represents a total maximum capacity of 2,400 Watts of active power.

To calculate the current in Amps for a 12 Volt system, divide the device power rating in Watts by 12: Amps = Watts / 12.

Exactly 1.0 Amp. This is calculated using the power equation: 12 Watts / 12 Volts = 1.0 Amp.

Exactly 220 Watts of active power, calculated as: 1 Amp × 220 Volts = 220 Watts.

Approximately 8.33 Amps. Sizing the current load yields: 100 Watts / 12 Volts ≈ 8.33 Amps.

Battery capacity in Amp-hours (Ah) is calculated by dividing total stored energy in Watt-hours (Wh) by the nominal voltage: Ah = Wh / 12V.

Standards and References

The formulas and reference values on this page follow these standards. For design work, check results against the current edition that applies in your country and the equipment manufacturer's data.

Nadeem Sial

Nadeem Sial

Senior Electrical Engineer

This calculator and technical guide were developed and verified by Nadeem Sial to ensure engineering and calculation precision. View Full Profile →

Related Calculators

Power System

Wh to Volts Calculator

Use our free Wh to Volts Calculator to calculate electrical parameters and convert power system units.

Open calculator
Power System

Volts to mAh Calculator

Use our free Volts to mAh Calculator to calculate electrical parameters and convert power system units.

Open calculator
Power System

Hz to Volts Calculator

Use our free Hz to Volts Calculator to calculate electrical parameters and convert power system units.

Open calculator