Electrical calculations · Android
Watt to Amp Calculator
Watts to amps for DC, single-phase and three-phase AC — plus a breaker load check for every circuit.
Convert watts to amps in one screen and compare the total current of your appliances with a circuit breaker rating.
Calculate as you type
- Enter any two of watts, amps, volts or ohms; the rest updates instantly.
- DC, single-phase AC and three-phase AC, with line-to-line or line-to-neutral voltage.
- Power factor and apparent power in kVA for AC loads.
- Regional voltage presets, from 12/24/48 V DC to 230 V and 400 V three-phase.
- Results stay pinned at the top, above the keyboard or an ad.
Check the whole circuit
Add appliances and compare total current with a 10, 13, 16, 20 or 32 A breaker. The gauge marks 80% for continuous loads, warns above 80% and shows “Overloaded” above 100%.
A built-in library covers 40 common appliances, with typical power ranges and their sources.
Free and Pro
Free: calculator and circuit load checks, with banner ads.
Pro: one-time purchase, no subscription. Unlimited loads, saved circuit projects, PDF load reports, recent calculation history and no ads.
Calculations work offline. No account is required. Your calculations and projects stay on your device. Advertising, consent and purchases use the third-party services described in the privacy policy.
Made for electricians, technicians, solar and generator installers, students and DIY homeowners.
Frequently asked questions
What does this watt to amp calculator calculate?
It calculates current from power and voltage for DC, single-phase AC and three-phase AC. Enter any two of watts, amps, volts or ohms to calculate the rest.
How do I convert watts to amps for DC?
Current = Power ÷ Voltage. For example, 120 W ÷ 12 V = 10 A.
What is the single-phase AC formula?
Current = Power ÷ (Voltage × Power factor). Enter a power factor greater than 0 and no greater than 1.
What is the three-phase AC formula?
Current = Power ÷ (√3 × line-to-line Voltage × Power factor). For example, 15 kW at 400 V L-L with PF 0.85 gives 15,000 ÷ (√3 × 400 × 0.85) = 25.47 A.
How does a circuit load check work?
Add the loads on one circuit. For example, 2,200 + 1,000 + 700 W at 230 V gives 3,900 ÷ 230 = 16.96 A, or 84.8% of a 20 A breaker. This example assumes single-phase loads with power factor 1. The gauge marks 80% for continuous loads; this reference does not determine code compliance or whether a breaker will trip.
Which units and voltage presets can I use?
Enter power in W or kW and view current in A or mA. Voltage presets include 230 V, 120/240 V, 400 V three-phase and 12/24/48 V DC.
Does the app work offline, and where are projects stored?
Calculations work offline. Calculation history and saved circuit projects are stored locally on your device. No account is required. The free version uses Google Mobile Ads and consent services; purchases use Google Play Billing.
What is included in Pro?
Pro is a one-time purchase with no subscription. It removes ads and unlocks unlimited loads, saved circuit projects, local PDF export or sharing, and recent calculation history.
Can I use this to select wiring or protection devices?
No. It is a calculation aid and does not replace electrical design, cable sizing, safety checks or applicable-code verification. Always check appliance nameplates, local wiring rules and a licensed electrician.
Reference only: always check appliance nameplates, local wiring rules and a licensed electrician. This app does not replace electrical design, cable sizing or code compliance checks.