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Electric Resistance Converter

Science

Convert electric resistance units: ohms, kilohms, megohms, and milliohms. Essential for electronics engineers, hobbyists, and circuit designers.

Reviewed by the thecalcu.com team · Last updated July 13, 2026

From
To
All conversionsfor 1 Kilohm (kΩ)
Microohm (μΩ)1000000000
Milliohm (mΩ)1000000
Ohm (Ω)1000
Kilohm (kΩ)1
Megohm (MΩ)0.001
Gigaohm (GΩ)0.000001

What is a Resistance?

An Electric Resistance Converter converts between units of electrical resistance, the property of a material that opposes the flow of electric current. Resistance is fundamental to all of electronics: every resistor, wire, motor winding, and contact junction has a resistance that determines how much current flows for a given voltage.

The SI unit is the ohm (Ω), defined by Ohm's law: one ohm is the resistance when one volt applied across a conductor produces one ampere of current (R = V/I). In practical electronics, resistance values span an enormous range, from microohms in superconducting contacts to gigaohms in high-impedance measurement circuits, which is why multiple prefix variants are in everyday use.

This converter covers 6 units in the SI prefix series:

  • Microohm (μΩ), contact resistance, busbar resistance, cable resistance
  • Milliohm (mΩ), battery internal resistance, motor winding resistance, PCB traces
  • Ohm (Ω), standard resistors, wire resistance, household circuits
  • Kilohm (kΩ), the workhorse unit of general electronics, pull-up resistors, voltage dividers, audio circuits
  • Megohm (MΩ), insulation resistance, high-impedance circuits, FET gate inputs
  • Gigaohm (GΩ), insulation quality testing, electrostatic charge measurements

For Indian electronics engineers and hobbyists, kilohm to ohm (and vice versa) is the most frequent conversion when reading resistor colour codes or translating circuit schematics. For electricians and maintenance engineers, megohm ↔ ohm is critical for insulation testing under IS 732 and motor maintenance protocols.

See the Electric Charge Converter for charge-related electrical calculations.

Why Use an Electric Resistance Converter?

Resistor values in electronics are written in shorthand: "4k7" means 4700 Ω, "10M" means 10,000,000 Ω, "220R" means 220 Ω. These notations mix units freely, and translating them to ohms for Ohm's law calculations requires consistent unit conversion.

Two concrete Indian use cases:

  1. Arduino project voltage divider: A hobbyist in Hyderabad builds a voltage divider with a 10 kΩ and 4.7 kΩ resistor to scale a 12V input to 5V for an Arduino analog pin. The output voltage is: Vout = 12 × (4700 ÷ (10000 + 4700)) = 12 × 0.3197 = 3.84V. Converting 4.7 kΩ to 4700 Ω is the first step in plugging values into Ohm's law.

  2. Motor insulation testing: A maintenance engineer in a Chennai textile mill tests a 415V induction motor winding with a megger. The reading is 22 MΩ. IS 732 requires minimum 1 MΩ for a 415V motor. Converting: 22 MΩ = 22,000 kΩ = 22,000,000 Ω, well above the minimum. Confirming units correctly prevents false-pass or false-fail decisions.

Who Should Use This Converter?

Electronics hobbyists and makers who read resistor values from colour codes or datasheets and need to convert between kΩ and Ω for Ohm's law calculations in Arduino, Raspberry Pi, and circuit design projects.

PCB designers and electrical engineers who work across scales, schematic values in kΩ and MΩ, Ohm's law calculations in Ω, and cable resistance in mΩ.

Electricians and electrical inspectors who measure insulation resistance in MΩ and GΩ using meggers, then compare against IS 732 and BIS standards that specify minimum values in MΩ.

Motor and transformer maintenance engineers who measure winding resistance in mΩ and Ω using micro-ohmmeters, then compare against baseline values to detect winding degradation.

Physics and electrical engineering students learning Ohm's law, Kirchhoff's laws, and circuit analysis, where resistance values must be converted to consistent units before computation. Pair with the Capacitance Converter for complete RC circuit analysis.

What Insights Does the Electric Resistance Converter Give You?

The converted value gives you the direct ohm-family equivalent, essential before plugging values into Ohm's law (V = IR) or power formulas (P = I²R).

The reference table shows your input resistance in all 6 units simultaneously, useful when a schematic shows resistance in kΩ, your calculation needs Ω, and your test equipment displays in MΩ.

Practical resistance reference:

Component Typical Resistance
Copper wire (1m, 1mm²) ~17 mΩ
LED current limiter 220 Ω – 1 kΩ
Arduino pull-up 4.7 kΩ – 10 kΩ
Insulation (cable, healthy) > 1 MΩ
Human body (dry skin) 100 kΩ – 1 MΩ
Good earth ground < 1 Ω

How to use this Resistance calculator

  1. The converter loads with Kilohm (kΩ) as the FROM unit and Ohm (Ω) as the TO unit, the most common conversion in general electronics.
  2. Select your source unit from the FROM dropdown: μΩ, mΩ, Ω, kΩ, MΩ, or GΩ.
  3. Enter the resistance value in the input field. Results update instantly.
  4. Select your target unit from the TO dropdown.
  5. Use the ⇅ swap button to reverse, useful when converting ohms from a calculation back to kilohms for a component selection.
  6. Scroll to the reference table to see the resistance in all 6 prefix variants simultaneously.
  7. Use the converted value in Ohm's law (I = V/R, V = IR, P = V²/R) for your circuit calculations.

Formula & Methodology

This is a linear converter using the ohm (Ω) as the common base unit. All conversions follow:

Result = Input × (toBase_from ÷ toBase_to)

Key toBase values (ohms):

| Unit | Ohms |
|---|---|
| Microohm (μΩ) | 1 × 10⁻⁶ |
| Milliohm (mΩ) | 1 × 10⁻³ |
| Ohm (Ω) | 1 |
| Kilohm (kΩ) | 1,000 |
| Megohm (MΩ) | 1,000,000 |
| Gigaohm (GΩ) | 1,000,000,000 |

All prefix multipliers are exact per SI definitions.

Worked example, Arduino LED circuit in Bengaluru:
An LED requires 20 mA at 2V forward voltage, powered from 5V. Required limiting resistance:

R = (5V − 2V) ÷ 0.020 A = 3V ÷ 0.020 A = 150 Ω

Nearest standard E12 value: 150 Ω (exact match in E12 series).
In kΩ: 150 ÷ 1000 = 0.15 kΩ.
Power dissipated in resistor: P = I²R = (0.020)² × 150 = 0.06 W, a standard ¼W resistor handles this safely.

Ohm's law quick reference:

| V | R | I |
|---|---|---|
| 5V | 1 kΩ | 5 mA |
| 5V | 10 kΩ | 0.5 mA |
| 12V | 100 Ω | 120 mA |
| 230V | 1 MΩ | 0.23 mA |

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Frequently Asked Questions

Electric resistance is the opposition that a material or component offers to the flow of electric current. The SI unit of resistance is the ohm (Ω), named after German physicist Georg Simon Ohm. One ohm is defined as the resistance between two points when a voltage of one volt produces a current of one ampere. Resistance depends on the material, geometry, and temperature of the conductor.
These are all units of electric resistance, differing by factors of 1000. One kilohm (kΩ) equals 1000 ohms, and one megohm (MΩ) equals 1,000,000 ohms. Resistors used in audio circuits are typically in the kilohm range (1 kΩ to 100 kΩ); resistors used in voltage dividers and pull-up resistors are often 4.7 kΩ to 10 kΩ; insulation resistance of cables is measured in megohms; and very high-impedance circuits (FET gate inputs, electrostatic sensors) may reach gigaohms.
A 10 kΩ resistor has a resistance of 10,000 ohms (10 kilohms). When 5V is applied across it, the current flowing is 5 ÷ 10,000 = 0.0005 A = 0.5 mA (by Ohm's law: I = V/R). 10 kΩ is one of the most common resistor values in electronics, used as pull-up resistors on I²C buses, in voltage divider circuits, and as current-limiting resistors for LEDs with current requirements below 0.5 mA.
To convert kilohms to ohms, multiply by 1000. For example, 4.7 kΩ = 4700 Ω. To convert megohms to kilohms, multiply by 1000: 1 MΩ = 1000 kΩ. To convert ohms to kilohms, divide by 1000: 47,000 Ω = 47 kΩ. The converter handles these calculations instantly, select your source unit in the FROM dropdown, enter the value, and select the target unit in the TO dropdown.
Indian electronics manufacturers, PCB designers, and repair technicians work with the full range of ohm prefix variants. Resistor component values in India are specified in the same E-series values used globally: E12, E24, and E96 series spanning from milliohms to megohms. Insulation resistance testing (as per IS 732 for electrical installations and IS 694 for cables) is specified in megohms and gigaohms. Motor winding resistance is typically in the milliohm to ohm range, measured with microohm meters in motor rewinding workshops.
Insulation resistance is the resistance of electrical insulation materials (cable sheathing, motor winding insulation, panel wiring) to current leakage. Healthy insulation has very high resistance, millions of ohms, so megohms (MΩ) and gigaohms (GΩ) are the practical units. IS 732 (electrical installations) requires insulation resistance of at least 1 MΩ; motor winding insulation below 1 MΩ per kV of rated voltage indicates moisture damage or degradation. Indian electrical inspectors and maintenance technicians use insulation resistance testers (meggers) calibrated in MΩ and GΩ.
Ohm's law states that V = I × R, where V is voltage in volts, I is current in amperes, and R is resistance in ohms. Rearranging: R = V/I (resistance equals voltage divided by current) and I = V/R (current equals voltage divided by resistance). For example, a 12V battery connected through a 100Ω resistor produces 12/100 = 0.12 A = 120 mA of current. Understanding Ohm's law is fundamental to electronics and is the primary reason for converting between resistance units.
Milliohms (mΩ) and microohms (μΩ) measure very low resistances found in: battery internal resistance (50–200 mΩ for typical lithium cells), contact resistance at connectors and switches (1–10 mΩ), motor winding resistance (often 0.1–5 Ω for small motors), cable resistance (copper cable resistance is about 17 μΩ·m), and PCB trace resistance. Low-resistance measurements are critical for EV battery health monitoring, motor efficiency analysis, and power distribution system design.
Select your source unit from the FROM dropdown, for example, Kilohm (kΩ). Enter the resistance value in the input field. Select the target unit from the TO dropdown, for example, Ohm (Ω). The result appears immediately. Use the ⇅ swap button to reverse the direction, and scroll to the reference table to see the resistance value in all six units simultaneously.
Common resistor value ranges by application: LED current-limiting resistors are typically 220 Ω to 1 kΩ; pull-up/pull-down resistors in digital circuits are 4.7 kΩ to 10 kΩ; audio volume potentiometers are 10 kΩ to 100 kΩ; RF circuit impedances are typically 50 Ω (coaxial) or 75 Ω (video); motor winding resistances range from 0.5 Ω (large motors) to 100 Ω (small DC motors); ground path resistance in power systems should be below 1 Ω per IS 3043.
All resistance units are linear multiples of the ohm: Result = Input × (toBase_from ÷ toBase_to). Key toBase values: 1 mΩ = 0.001 Ω; 1 kΩ = 1000 Ω; 1 MΩ = 1,000,000 Ω; 1 GΩ = 1,000,000,000 Ω. For example, to convert 4.7 MΩ to kΩ: 4.7 × 1,000,000 ÷ 1000 = 4700 kΩ.
Also known as
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