Resistance Calculator

Calculate electrical resistance using Ohm's Law and power formulas. Enter any two known values to find the resistance and other electrical parameters.

Resistance Calculation Formulas

R = V / I
Ohm's Law
R = P / I²
Power & Current
R = V² / P
Power & Voltage

Note: Enter any two values to calculate the resistance and other parameters.

About Electrical Resistance

Electrical resistance is the opposition to the flow of electric current. It is measured in ohms (Ω) and determines how much current will flow for a given voltage.

Factors Affecting Resistance:

  • Material: Different materials have different resistivities
  • Length: Longer conductors have higher resistance
  • Cross-sectional area: Thicker conductors have lower resistance
  • Temperature: Most materials' resistance changes with temperature

Resistance Units:

  • Ohm (Ω): Base unit of electrical resistance
  • Kiloohm (kΩ): 1,000 ohms
  • Megohm (MΩ): 1,000,000 ohms
  • Milliohm (mΩ): 1/1000 of an ohm

Applications:

  • Circuit design and analysis
  • Component selection
  • Current limiting
  • Voltage division
  • Heating elements