Power of a 5 V USB Device Drawing 500 mA
A USB 2.0 device at 5 V drawing 500 mA consumes 2.5 W.
How to use this tool
- Enter known values, voltage v, current i, resistance r and power p in the fields above.
- Results update instantly as you type ā or click Calculate.
- Read your power p and the full breakdown beneath it.
Standard USB 2.0 supplies up to 500 mA at 5 V, giving a maximum power delivery of 2.5 W.
Frequently asked questions
- How is this different from the Ohm's Law calculator?
- The Ohm's Law calculator solves V=IR for three variables. This tool adds the power equations (P=VI, P=IĀ²R, P=VĀ²/R) and lets you start from any two of the four quantities P, V, I, R.
- What are real-world examples?
- A 60 W light bulb on 120 V draws I = P/V = 0.5 A, with R = V/I = 240 Ī©.