Resistance Converter

Our free online Resistance Converter lets you instantly convert electrical resistance values between ohms (Ω), milliohms (mΩ), kilohms (kΩ), and megohms (MΩ). Whether you are reading a resistor color code, checking a datasheet, or designing a circuit, this tool gives you accurate conversions with a full unit table and a clear step-by-step breakdown.

How to Use the Resistance Converter

Enter any resistance value in the input field, select the source unit from the dropdown, and choose the target unit. The converted value appears instantly along with a complete table showing the equivalent value in every supported unit. Use the Swap button to quickly reverse the conversion direction.

For example, enter 1 and select Ohm (Ω) as the source with Kilohm (kΩ) as the target to see that 1 Ω equals 0.001 kΩ and 1e-6 MΩ.

Supported Resistance Units

• Ohm (Ω): The SI base unit of electrical resistance. One ohm is the resistance between two points of a conductor when a constant potential difference of one volt produces a current of one ampere.
• Milliohm (mΩ): One thousandth of an ohm (1 mΩ = 0.001 Ω). Used for very small resistance values such as contact resistance, shunt resistors, and PCB trace resistance.
• Kilohm (kΩ): One thousand ohms (1 kΩ = 1,000 Ω). The most common unit for resistors in consumer electronics and signal circuits.
• Megohm (MΩ): One million ohms (1 MΩ = 1,000,000 Ω). Used for high-value resistors in voltage divider networks, sensor biasing, and insulation measurements.

Conversion Formula

Resistance conversions use the ohm as the common base unit. The calculator converts your source resistance into ohms first, then expresses the same electrical resistance in the target unit:

Result = Value × (Source factor ÷ Target factor)

Where each factor maps the unit to the ohm: 1 Ω = 1, 1 mΩ = 0.001, 1 kΩ = 1,000, 1 MΩ = 1,000,000.

Applications

• Circuit Design: Reading and comparing resistor values specified in different units on schematics and datasheets
• Power Systems: Checking very small connection and contact resistances in milliohms for switchgear and bus bars
• Insulation Testing: Interpreting large resistance values in megohms for cable and equipment insulation tests
• Education: Learning the relationship between resistance unit prefixes and practicing unit conversions

Also check: Resistor Calculator, Voltage Drop Calculator, Power Calculator, RC RL Time Constant Calculator, Unit Converter, and Work Calculator.