Ohm's Law/Power Law Calculator

467 reviews
Content rating
Screenshot image
Screenshot image

About this app

Ohm's law and the power law describe the relationship between the following four electrical entities:


Current...........Amps.....A, I
Resistance.....Ohms.....Ω, R

Ohm's law: Voltage = Current x Resistance
Power law: Power = Voltage x Current

Set any two, and the other two can be calculated.

This application allows you to continually lock one parameter and input another, enabling rapid "what-if" recalculation.

Use the keypad to enter a value then tap on the parameter you want to set. It is now fixed, as shown by the padlock symbol.

Enter another parameter and the remaining two are calculated. The most recently entered parameter becomes the new fixed one.

You can alter which parameter is fixed by tapping it when the input box is empty, or by dragging the padlock to it.

You can "Freeze" a parameter with a long press until it changes color. Now alter any of the other three as required. To unfreeze, with the input box empty, tap any other parameter.

The value of the fixed parameter may not be changed. If you attempt to do so, the padlock will flash. In this case, fix another parameter first.

Available in the following Languages:
English, French, German, Swedish, Russian, Polish, Spanish, Italian, Traditional & Simplified Chinese.
Updated on
Nov 3, 2013

Data safety

Developers can show information here about how their app collects and uses your data. Learn more about data safety
No information available

Ratings and reviews

436 reviews
A Google user
November 29, 2021
Great app easy to use brilliant
Did you find this helpful?
A Google user
March 2, 2015
Great wee app. Great time saving device as we had to manually configure wind turbine dump load values. Well done.
2 people found this review helpful
Did you find this helpful?
A Google user
December 19, 2017
Enter a second field and it just wipes out other entries. Doesn't work.
Did you find this helpful?

What's new

Added localizations for Traditional & Simplified Chinese