About this converter
Electrical resistance is the opposition a conductor offers to the flow of electric current, measured in ohms (Ω) — the SI unit named after Georg Simon Ohm. One ohm is the resistance that produces a voltage drop of 1 volt when carrying 1 ampere. Ohm's law (V = IR) links resistance, voltage, and current in a relationship used across all electrical disciplines.
Electricians, electronic engineers, and materials scientists work with resistance values spanning many orders of magnitude — from microohms in copper bus bars to gigaohms in insulating ceramics. This converter handles the most useful scales: ohm, megohm, microohm, abohm, statohm, and the quantized Hall resistance used as a precision metrology standard.
How to Use This Converter
- Enter the resistance value in the Value field.
- Select the source unit from the From dropdown.
- Select the target unit from the To dropdown.
- The converted value and formula line update instantly.
- Use Swap to check both conversion directions.
Units Covered
| Unit | Symbol | Common Use |
|---|---|---|
| Ohm | Ω | SI unit; universal in circuit design, component ratings, and measurements. |
| Megohm | MΩ | Insulation resistance, leakage testing, and high-impedance circuits. |
| Microhm | µΩ | Bus bar resistance, contact resistance, and low-loss winding checks. |
| Volt/ampere | V/A | Equivalent to ohm; used in power-law resistance definitions. |
| Reciprocal siemens | 1/S | Equivalent to ohm; used when relating resistance to conductance. |
| Abohm | abΩ | CGS electromagnetic unit; 1 abΩ = 10⁻⁹ Ω. |
| EMU of resistance | emu | Same as abohm in the CGS-EM system. |
| Statohm | statΩ | CGS electrostatic unit; 1 statΩ ≈ 8.988 × 10¹¹ Ω. |
| ESU of resistance | esu | Same as statohm in the CGS-ES system. |
| Quantized Hall resistance | R_K | Quantum standard; R_K = 25,812.807 Ω, used in precision metrology. |
Ohms to Megohms Conversion Table
| From | To |
|---|---|
| 1,000 Ω | 0.001 MΩ |
| 10,000 Ω | 0.01 MΩ |
| 100,000 Ω | 0.1 MΩ |
| 500,000 Ω | 0.5 MΩ |
| 1,000,000 Ω | 1 MΩ |
| 2,000,000 Ω | 2 MΩ |
| 5,000,000 Ω | 5 MΩ |
| 10,000,000 Ω | 10 MΩ |
| 100,000,000 Ω | 100 MΩ |
| 1,000,000,000 Ω | 1000 MΩ |
How to Convert Ohms to Megohms
Ohms to megohms
For example, 4,700,000 Ω / 1,000,000 = 4.7 MΩ — a common high-impedance resistor value.
Megohms to ohms
For example, 100 MΩ × 1,000,000 = 100,000,000 Ω — a typical insulation resistance acceptance threshold.
When You Need to Convert Resistance
PCB and wiring harness engineers measure trace and contact resistance in microohms and milliohms. A 1-inch 1 oz copper trace (0.3 mm wide) has about 180 mΩ of resistance. Contact resistance for gold-plated connectors is typically below 10 mΩ. Converting µΩ readings from four-wire milliohmmeter tests to Ω for Ohm's law power calculations is standard in reliability testing.
Insulation resistance testing — performed with a megohmmeter — verifies cable, transformer, and motor winding integrity in megaohms. A motor winding with 100 MΩ insulation resistance is healthy; below 1 MΩ per 1000 V of rating indicates a fault risk. Converting megohmmeter field readings to ohms for simulation inputs or comparing IEC 60364 limits requires precise MΩ↔Ω conversion.
Precision metrologists use the quantized Hall resistance (R_K = 25,812.807 Ω) as the international standard for resistance. National metrology institutes calibrate working resistance standards against R_K, traceable to the quantum Hall effect. This traceability chain — from R_K in ohms to kilohms and megaohms used in calibration labs — depends on exact resistance unit conversions at each step.