Home / Ohm’s Law Pie Chart – Quick and Easy

Ohm’s Law Pie Chart is a great tool to make quick electric calculations (see a picture). It includes twelve patterns which address any mode of famous electric law. Instead of searching for reference to one of these particular formulas somewhere else, here you cover all the calculation approaches to Ohm’s principal at this single easy-to-use chart. The chart is seeable and understandable. It is fun to use even for kids, and it’s tasty – remember, it’s a “pie”!

Ohms Law Pie Chart

How to use Ohm’s Law Pie Chart

The Ohm’s Law Chart is divided into four main quarters. We’ve got twelve pie slices around. In the inner circle we have four variables. These variables are what we don’t know, what we are trying to find:

“P” – for Power

“E” – for Electromotive Force

“R” – for Resistance

“I” – for Current


The slices of the pie represent given/known data in each case.


Each of the variables we are trying to find has three pie slices – three equations. Now, depending on what two numbers (two types of data) we know – we choose the appropriate equation which would fit our interest and resolve the question.


For example, you need to calculate Power using Ohm’s law formulas and you know, let’s say Electromotive Force value and a Current value. Power is “P” so you choose left upper (red) quarter of the chart to begin with. Now, Electromotive Force is “E” and a Current is “I”. Take a look at the slices in quarter “P” and find out which one of the three corresponding pie slices has BOTH: E and I. In this case it is the slice on the left hand side which says:

“E x I” which means


P = E x I (“P” is equal “E” multiplied by “I”)


So just multiply the two numbers you already know and get the result. That’s it!


You could calculate a value of any variable in the chart using this principal of finding the appropriate formula.


. . . . . . . . . . . . . . . . .


Theoretical excursion


Georg Ohm - author of famous law

Ohm’s law states that the current through an electric transmitter between two spots is straightly proportional to the electromotive force across the two points. Introducing the unchanging factor of proportionality – the resistance, the logic arrives at the mathematical equation that describes this relationship where the current (“I”) through the conductor in units of amperes, the electromotive force (“E”) measured across the conductor in units of volts, and the resistance (“R”) of the conductor in units of ohms all bound in a certain relation of proportionality: E = I x R. More specifically, this rule states that the impedance in this relation is constant, independent of the current.


The Law was named after the German physicist Georg Ohm, who, in a monograph published in 1827, reported measurements of applied voltage and current through regular electrical circuits containing diverse lengths of wire. He presented a slightly more complex equation than the one we all know today to explain the main discovery which was result of series of experiments. The widely known equation E = I x R is the modern form of Ohm’s principal.

Shopping Cart

No products in the cart.

Delivery (header content) English Language

Delivery is from US only.

We will deliver to a home or work address in our delivery areas, whichever is more convenient for you. How much does it cost and how long does it take?

  • $3.99 Next day home delivery – NEW now order up until 10pm
  • $3.50 Standard home delivery – get your order within 13 working days. FREE when you spend $50 or more
  • Free nominated day delivery on orders over $100

International Delivery

We deliver to over 20 countries including Europe, South America & USA. Please note that not everything we sell online is available for international delivery. For more detail on delivery charges and timescales by country, please contact us at info@polyhardware.com

Chicago Main Office

Chicago Main Office
600 Northgate Pkwy Suite H, Wheeling, IL 60090

ph: 1-847-808-9000

fax: 1-847-808-9011

e-mail: info@polyhardware.com

web: www.electrausa.wpengine.com

Trusted Partners

Customer Service

Technical Support

Our support line is available 24/5 a day

Phone: +(847)808-9000 Fax : +1(847) 808-9011 Email: info@polyhardware.com

Contact Us (header content) Sliding Panel

Contact Us

600 Northgate Parkway.# H
Wheeling, IL 60090, USA

Give Us a RIng

Email Us


Tu nombre (requerido)

Tu correo electrónico (requerido)

Tu mensaje

We Are Here

Social media & sharing icons powered by UltimatelySocial