Ohm’s Law Calculator for Voltage, Current, Resistance, and Power

Ohm’s Law is a fundamental principle in electrical engineering and physics, describing the relationship between voltage, current, and resistance in an electrical circuit. It states that the current through a conductor between two points is directly proportional to the voltage across the two points and inversely proportional to the resistance between them.

Ohm’s Law can also be extended to include the concept of electrical power. Power in an electrical circuit is the rate at which electrical energy is converted to another form of energy, such as heat, light, or mechanical energy. The unit of power is the watt (W).



What is Ohm's Law?

Ohm’s Law (E = IR) is a formula used to calculate the relationship between voltage, current and resistance in an electrical circuit.

The full forumal is E = I x R where E = Volts, I=current (in amps), and R=resistance. This is also sometimes annoted as voltage = current x resistance, or volts = amps x ohms, or V = A x Ω.

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Popular manufacturers

The table below highlights our wide range of leading resistor manufacturers and some of their key attributes:

Caddock Electronics Resistors
  • High performance, high stability film SMD as well as axial and radial through-hole resistors
  • Precision low and high ohmic, high voltage, high temperature and non-inductive high power resistors

Click here to see Caddock's range of resistors.

Exxelia Ohmcraft Resistors
  • High performance, high voltage and high ohmic thick film SMD and through-hole resistors
  • Utilises Micropenning® to offer the most precise and stable high voltage, high ohmic resistor packages available

Click here to see Exxelia Ohmcraft's range of resistors.

General Resistance Resistors
  • High precision, high stability, wirewound through-hole resistors
  • Standard tolerances of ±0.01% and ±0.1% available with a TCR of 5ppm/°C maximum between -55°C and +125°C

Click here to see General Resistance's range of resistors.

Isabellenhütte Resistors
  • Low ohmic, precision and power SMD and through-hole resistors with excellent current and pulse handling capabilities
  • 2 and 4-terminal designs available in both SMD and through-hole packages as well as automotive and space approval on various products

Click here to see Isabellenhütte's range of resistors.

RARA Resistors
  • State-of-the-art high power metal clad wirewound resistors and resistor assemblies
  • Both inductive and non-inductive designs in various package types with UL approved and IP65 rated options available on select models

Click here to see RARA's range of resistors.

Riedon Resistors
  • Specialist high power, wirewound, precision resistors including precision current and DC current base mounted shunts
  • Excellent high pulse, high temperature resistors with a wide range of tight TCR and tolerance options

Click here to see Reidon's range of resistors.

SRT Resistor Technology
  • High voltage, high ohmic, high temperature thick film resistors with high temperature variants available up to +300°C
  • High ohmic resistors, up to 10TΩ, and high voltage resistors with Non-magnetic models available in both SMD and through-hole packages

Click here to see SRT's range of resistors.

Susumu Resistors
  • Ultra-high precision, thin film SMD resistors and resistor networks
  • Specialist in thin film and metal foil SMD resistors covering a wide range of resistance values and applications

Click here to see Susumu's range of resistors.

VPG Foil Resistors Logo
  • Ultra-high precision and stability Bulk Metal® foil resistors
  • SMD and Through-hole, ultra-high precision, current sensing, voltage dividers and network options available

Click here to see VPG Foil Resistor's range of resistors.

Users are hereby informed that Rhopoint accepts no responsibility for any inaccuracies or issues that may arise from the use of our online calculators. All data and results should be independently verified prior to their application in any projects or calculations.

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