Power Calculator
Keep ideal power separate from an explicitly entered arithmetic factor; optional seconds also produce joules.
Positive input range: 0.000001–1,000,000,000. Duration is optional. No factor is assumed.
Ideal DC / pure-resistive arithmetic only. A user factor is an arithmetic multiplier, not a shore-power or breaker rating. No AC, power factor, or safety approval is modeled.
P = V × I or P = I² × R; E = P × t; adjusted values = ideal values × factor / 100
Enter values and calculate.
Power
A QUICK WALKTHROUGH
How to use this tool
- Choose voltage + current or current + resistance.
- Enter positive inputs within the stated bounds; optionally enter duration in seconds.
- Choose ideal values or enter a user factor from 0 to 100. Calculate, copy, or download the result.
Two retained formulas
Voltage and current use P = V × I; current and resistance use P = I² × R. The optional duration uses E = P × t, where one watt-second is one joule.
Explicit factor, separate results
Only the user-factor mode requires a percentage. Zero and 100 are valid. Ideal power remains visible; adjusted power and energy multiply the ideal results by that percentage. No percentage is prefilled.
Local bounded arithmetic
Selected electrical inputs and any duration must be finite and between 0.000001 and 1,000,000,000. Non-finite results and nonzero values lost to numeric underflow are rejected. All calculation and TXT export stay in this browser.
GOOD TO KNOW
Common questions
Is this an AC or shore-power rating?
No. It does not model AC phase or power factor, certify a breaker, or approve a continuous-load allowance. The user factor only scales arithmetic.
Is the factor an efficiency recommendation?
No. Choose a factor for your own stated arithmetic purpose. No efficiency, safety margin, or charging behavior is assumed.
Can I omit duration and the factor?
Yes. Ideal mode needs only the chosen electrical pair. Duration is optional; the factor is required only after selecting user-factor mode.