Quick Answer: Watts to Amps
One watt equals 0.00434782609 amps at 230 V (1 W = 0.00434782609 A).
Conversely, 1 A = 230 W at 230 V.
Formula: A = W ÷ 230 V
Worked examples
- 100 W = 0.434782609 A at 230 V
- 500 W = 2.17391304 A at 230 V
- 1000 W = 4.34782609 A at 230 V
Method and limitations
Current equals power divided by voltage (I = P ÷ V). Because the answer depends on supply voltage, enter it in the calculator — 230 V single-phase for Europe (IEC 60038), 120 V for a standard North American circuit, or your actual DC voltage. Every formula, table and example on this page follows the voltage you select. Calculations use full-precision constants; displayed values are rounded to at most 9 significant figures. This is not a fixed unit pair. The result depends on supply voltage, so always state the supply voltage (230 V here) alongside the answer.
Each factor is exact by definition, derived from exact definitions, or a documented conventional value — see the methodology and sources.
Conversion Formula
Current equals power divided by voltage (I = P ÷ V). Because the answer depends on supply voltage, enter it in the calculator — 230 V single-phase for Europe (IEC 60038), 120 V for a standard North American circuit, or your actual DC voltage. Every formula, table and example on this page follows the voltage you select.
This formula uses the supply voltage currently set in the calculator (230 V). Change it above and this formula updates with it — the relationship is not a fixed unit pair.
Complete Guide to Watts to Amps Conversion
What is a Watts?
The watt (W) is the SI unit of power — the rate of energy transfer, equal to one joule per second. Appliance nameplates, solar panels and chargers are all rated in watts or kilowatts.
What is a Amps?
The ampere (A) is the SI base unit of electric current, measuring the flow of charge. Circuit breakers, cables, plugs and EV chargers are all rated in amps because current determines heating in the conductor.
How the Conversion Works
Ohm's power law states that power equals voltage multiplied by current. Rearranged, current equals power divided by voltage. This calculator uses 230 V, the harmonised single-phase supply voltage across Europe. For a US 120 V circuit, or a 12 V DC system, substitute that voltage instead.
Why This Conversion Matters
Cables and breakers are sized by current, not power. Every question about whether a circuit can run an appliance — an oven, a heat pump, a home EV charger — is really a question about amps. Getting this conversion wrong is how circuits overheat and breakers trip.
Scientific Context
For alternating current with inductive loads, real power (W) is apparent power (VA) multiplied by the power factor. Motors, compressors and older fluorescent lighting typically have a power factor of 0.8 to 0.95, so their actual current draw exceeds the simple W ÷ V result.
Step-by-Step Conversion Guide
Follow these steps to convert watts to amps manually:
Start with your value in watts
Example: You want to convert 1000 W
Apply the conversion formula
Use the formula: A = W ÷ 230 V
Calculate the result
1000 W = 4.3478 A
Verify your answer
Use our calculator above to double-check your manual calculation.
Quick Mental Math Tip
Current equals power divided by voltage (I = P ÷ V). Because the answer depends on supply voltage, enter it in the calculator — 230 V single-phase for Europe (IEC 60038), 120 V for a standard North American circuit, or your actual DC voltage. Every formula, table and example on this page follows the voltage you select.
Common Conversions
Calculated at 230 V (supply voltage). Change the value in the calculator above and this table recalculates.
| Watts (W) | Amps (A) | Amps → Watts |
|---|---|---|
| 100 W | 0.434783 | 100 A = 23,000 W |
| 500 W | 2.17391 | 500 A = 115,000 W |
| 1000 W | 4.34783 | 1000 A = 230,000 W |
| 1500 W | 6.52174 | 1500 A = 345,000 W |
| 2000 W | 8.69565 | 2000 A = 460,000 W |
| 2200 W | 9.56522 | 2200 A = 506,000 W |
| 3000 W | 13.0435 | 3000 A = 690,000 W |
| 3680 W | 16 | 3680 A = 846,400 W |
| 7400 W | 32.1739 | 7400 A = 1,702,000 W |
| 11000 W | 47.8261 | 11000 A = 2,530,000 W |
When You'll Need This Conversion
Circuit and cable sizing
Check that appliance current stays within breaker and conductor ratings.
EV charger installation
A 7.4 kW charger needs 32 A at 230 V — the number that determines the whole installation.
Workshop and site power
Verify that tools and machines fit the available supply before plugging in.
Camping and marine hookups
Shore power is sold in amps (typically 6 A, 10 A or 16 A) while appliances are labelled in watts.
Pro Tips for Accurate Conversions
Apply the 80% continuous rule
Anything running for more than three hours should stay below 80% of the breaker rating.
Know your voltage
230 V in Europe, 120 V in North America, 100 V in Japan. The same appliance draws very different current.
Divide by power factor for motors
A 2 kW motor at 0.85 power factor draws about 10.2 A, not 8.7 A.
Common Mistakes to Avoid
Using 240 V or 120 V without checking
Regional voltage differences change the answer by a factor of two.
Confirm the nominal supply voltage before sizing anything.
Ignoring inrush current
Motors and compressors draw several times their running current at startup.
Select breaker curves (type C or D) that tolerate startup surges.
Loading a breaker to its exact rating
Breakers are thermal devices and will trip near their limit under sustained load.
Design continuous loads to 80% of the rating.
History & Background
The ampere is one of the seven SI base units, named after André-Marie Ampère. Europe's harmonisation on 230 V in the 1990s finally gave the continent one number for these calculations.
Key Milestones
Ampère formulates the relationship between current and magnetic force.
The International Electrical Congress adopts the ampere, volt and watt.
CENELEC harmonises European supply voltage at 230 V ±10%.
The ampere is redefined from the fixed value of the elementary charge.
Global Usage Today
Most of the world uses 220–240 V single-phase supply; North America and Japan use 100–120 V, which doubles the current for the same appliance power.
Frequently Asked Questions
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Conversion factors on this page are either exact by definition, derived from exact definitions, or conventional values in documented use. Each is listed with its source in our conversion methodology and sources, which cites the BIPM SI Brochure, NIST Special Publication 811 and the relevant IEC or national standards. Results are rounded for display only; calculations use full precision.