Ohm's Law & Watt's Law Calculator

Ohm's Law & Watt's Law Training Calculator

Electrical Laws Training Calculator

This page is designed for radio and electronics training. It explains and applies Ohm’s Law and Watt’s Law, and shows how they work together in real circuits.


Ohm’s Law

Ohm’s Law defines the relationship between voltage (U), current (I), and resistance (R) in an electrical circuit. It states that voltage is equal to the product of current and resistance.

U = I × R

  • U – Voltage (volts, V)
  • I – Current (amperes, A)
  • R – Resistance (ohms, Ω)

Enter exactly two values to calculate the third.







Derived Power from Ohm’s Law


Watt’s Law

Watt's Law defines the relationship between power (P), voltage (U), and current (I) in an electrical circuit. It states that power is equal to the product of voltage and current.

P = U × I

  • P – Power (watts, W)
  • U – Voltage (volts, V)
  • I – Current (amperes, A)

Enter exactly two values to calculate the third.







Derived Power Formulas

  • P = I² × R = I x I x R
  • P = U² ÷ R = U x U / R