How to Calculate Ohms

A multimeter can measure ohms.
••• Gennady Kravetsky/Hemera/Getty Images

Ohms are the units that measure electrical resistance. Resistance is a property of a material that works in opposition to the free flow of electrons, and is the inverse of the conductance of the material. In a conductor such as a copper wire, voltage will propel electrons to create a current of electrons moving down the wire, akin to water moving in the current of a stream. Resistance works in opposition to this movement of electrons, akin to how friction created by a stream's banks, bed, and debris work in opposition to its current and slow the flow of the water. Resistance changes with changes in voltage and current. Calculating ohms is important in physics and, more specifically, in electronics.

    Determine the voltage of the battery in the system you're measuring. For instance, suppose you have a 9-V battery.

    Determine the current flowing through the circuit. You may need a multimeter to check this. This is the number of amps. For example, you may have 2 amps.

    Divide the volts by the amps. In the example, 9 V divided by 2 A equals 4.5 ohms.

Related Articles

How to Calculate Millivolts to Amps
How to Calculate IRMS
How to Change Electrical Amps to Watts
How to Calculate Potential Difference
How to Measure Wattage With a Multimeter
How to Calculate 30 KW to Amps
How to Calculate the Field Current in a DC Motor
How to Calculate KVA to MVA
How to Wire a Battery in Series
How to Calculate the Horsepower of a Compressor
How to Calculate the Henrys in a Coil
How to Calculate Kinetic Energy
How to Convert CV to GPM
How to Convert Ohms to Kilowatts
How to Calculate Battery Voltage
How to Convert 12 Volt Alternator to 120 Volts
How to Calculate Conductance
How to Calculate Output Voltage
Fun Facts About Simple Circuits
How to Measure the Ohm Value for an Inductor