RFrftools.io
Convert

Resistance Unit Converter

Convert resistance between milliohms, ohms, kilohms, megaohms, and gigaohms.

Loading calculator...

Formula

1 kΩ = 1000 Ω, 1 MΩ = 10⁶ Ω

How It Works

Resistance is measured in ohms (Ω), defined by Georg Simon Ohm. Common sub-multiples and multiples include milliohms (mΩ, 10⁻³ Ω) for shunt resistors and PCB trace resistance, kilohms (kΩ, 10³ Ω) for typical signal-path resistors, megaohms (MΩ, 10⁶ Ω) for high-impedance circuits, and gigaohms (GΩ, 10⁹ Ω) for insulation resistance testing.

Worked Example

A 10 kΩ pull-up resistor: 10 kΩ = 10,000 Ω = 10,000,000 mΩ = 10 MΩ × 0.001 = 0.01 MΩ = 0.00001 GΩ. A 10 mΩ current shunt: 10 mΩ = 0.01 Ω = 0.00001 kΩ = 0.00000001 MΩ.

Practical Tips

  • ✓Current sensing shunts are typically 1–100 mΩ to minimize power loss; use a four-wire (Kelvin) connection to avoid lead resistance errors.
  • ✓Resistor networks for RF impedance matching are most often 50 Ω or 75 Ω; always check the system impedance before selecting values.
  • ✓High-impedance circuits (input bias, feedback) often use 1–10 MΩ resistors, which are susceptible to surface leakage — keep PCB surfaces clean and use guard rings where needed.

Common Mistakes

  • ✗Confusing kΩ (kilohm, 1000 Ω) with MΩ (megaohm, 1,000,000 Ω) — they differ by 1000×.
  • ✗On schematics, 'R' can mean ohms (e.g., 4R7 = 4.7 Ω in European notation) while 'K' means kilohms.
  • ✗Insulation resistance is often specified in MΩ or GΩ; a reading of 1 GΩ is healthy, while 1 MΩ may indicate moisture ingress.

Frequently Asked Questions

Milliohm-range resistors appear as current sensing shunts, contact resistance specs, and PCB copper trace resistance calculations. Small resistances matter for power dissipation in high-current paths.
Divide by 1000: 4700 Ω = 4.7 kΩ. To convert kΩ to MΩ, divide by 1000 again.
Insulation resistance is measured in MΩ or GΩ and indicates how well an insulating material blocks current flow. Good insulation is typically >1 GΩ; values below 1 MΩ suggest degradation or contamination.
50 Ω is a compromise between the 77 Ω that minimizes coaxial cable loss and the 30 Ω that maximizes power handling, giving a practical balance for RF systems.

Related Calculators

Convert

Inductance Converter

Convert inductance between henries, millihenries, microhenries, nanohenries, and picohenries.

Convert

Capacitance Converter

Convert capacitance between farads, millifarads, microfarads, nanofarads, and picofarads.

General

Ohm's Law

Calculate voltage, current, resistance, and power using Ohm's Law. Enter any two values to solve for the remaining two quantities.

Convert

Frequency ↔ Wavelength

Convert frequency to wavelength in any medium. Calculates full, half, and quarter wavelengths for antenna design, transmission line, and RF system planning.

Convert

dBm ↔ Watts

Convert RF power between dBm, Watts, milliwatts, dBW, dBμV, and RMS volts into 50Ω. Essential for link budgets, amplifier analysis, and RF system design.

Convert

Temperature Converter

Convert temperature between Celsius, Fahrenheit, Kelvin, Rankine, and Réaumur scales. Useful for thermal analysis, datasheet comparison, and engineering calculations.