PHYSICS

Electrical power calculator

Calculate DC electrical power from voltage and current.

01 / INPUTS

Your numbers

02 / YOUR RESULT
24
Watts (W)

Default inputs are examples. Change them to match your situation.

How to use this calculator

Calculate DC electrical power from voltage and current. Enter voltage (v), current (a). The result updates when you change an input. To compare two sets of inputs, save scenario A, then enter the second set; the result panel shows the difference.

Formula and limits

DC power P = V × I. AC circuits may require a power factor and RMS quantities.

Worked example

The following example uses the calculator’s starting values. It is an illustration of the method, not a recommended target.

InputExample value
Voltage (V)12
Current (A)2

Watts (W): 24

Interpreting your result

Match every quantity to its labeled unit before calculating. The model stated below may assume ideal components, constant acceleration, or classical mechanics; check that those assumptions fit the situation.

Comparing alternatives

Save the first result as scenario A, then change one input. The comparison shows the numeric difference; it does not label either result as better. Choose inputs that describe realistic alternatives. Values shown on screen are rounded, so calculations from rounded intermediate results may differ slightly.

Background reading

OpenStax College Physics. This is a subject reference, not an endorsement or independent review of Calcaven.

Implementation updated September 25, 2026 · How we check calculations