Amperage Calculator is a free, fast, and accurate online tool built for anyone who needs to calculate electrical current — from students learning Ohm's Law to electricians sizing circuits and homeowners checking appliance loads.
Our Story
Amperage Calculator was born out of a simple need: finding a reliable, easy-to-use electrical current calculator online shouldn't be difficult. Yet most tools were either buried in ad-heavy pages, limited to a single formula, or lacked the interactive visualizations that make electrical concepts click.
We built Amperage Calculator to be the definitive resource for calculating amps. Whether you need to find current from voltage and resistance, power and voltage, or power and resistance — our tool handles it instantly with an interactive circuit diagram that shows you exactly how electricity flows.
Who It's For
- Students — Learning Ohm's Law, circuit analysis, and electrical engineering fundamentals.
- Electricians — Quickly verifying amperage calculations for circuit sizing and wire gauge selection.
- Engineers — Designing circuits, selecting components, and validating electrical specifications.
- DIY Enthusiasts — Planning home electrical projects and understanding appliance loads.
- EV Owners — Calculating charging current requirements and circuit capacity.
- Renewable Energy — Sizing solar panels, inverters, and battery systems.
What We Offer
- Three Calculation Methods — Calculate amps from V&R, P&V, or P&R with real-time results.
- Interactive Circuit Diagram — Visualize electron flow with adjustable voltage and resistance.
- Ohm's Law Reference — Formula cards with examples and the Ohm's Law triangle.
- Device Reference Table — Common amperage values for everyday appliances.
- Step-by-Step Guide — Learn how to calculate amperage from scratch.
Our Principles
- Accuracy — Our calculations follow standard electrical formulas and Ohm's Law precisely.
- Instant Results — Real-time calculation as you type, no page reloads or submit buttons.
- Privacy First — All calculations happen locally in your browser. We never store your data.
- Accessibility — Works on any device with a web browser — desktop, tablet, or phone.
- Free Forever — No sign-ups, no subscriptions, no hidden costs.
Safety Note
While our calculator provides accurate results based on Ohm's Law, electrical work can be dangerous. Always consult a qualified electrician for professional electrical installations and modifications. Our tool is designed for educational and reference purposes — never rely solely on any online calculator for safety-critical electrical decisions.
Looking Ahead
We're constantly improving Amperage Calculator. Future updates may include three-phase power calculations, wire gauge recommendations, circuit breaker sizing tools, and more interactive visualizations. If you have suggestions, we'd love to hear from you on our Contact page.
Get in Touch
Have a question, suggestion, or found a bug? Visit our Contact page to reach out. We read every message.