An ohm (Ω) is the SI unit of electrical resistance. It is defined as the resistance between two points where 1 volt causes 1 ampere of current (Ω = V/A).

How many ohms is 1 kilohm?

1 kilohm (kΩ) = 1,000 ohms. 1 megaohm (MΩ) = 1,000 kΩ = 1,000,000 Ω.

Ohm's law states that V = I × R, where V is voltage (volts), I is current (amperes), and R is resistance (ohms). If resistance doubles, current halves for the same voltage.

Resistance Converter

How to Use the Resistance Converter

Enter the resistance value in the Value field and select the unit you are converting from. All equivalents update instantly.

Electrical Resistance Units

Electrical resistance is the opposition to current flow in a circuit. The SI unit is the ohm (Ω), named after physicist Georg Simon Ohm. It is defined as V/A (volts per ampere).

Microohm (μΩ) — 10⁻⁶ Ω. Resistance of very short wire segments, superconductor contacts.
Milliohm (mΩ) — 10⁻³ Ω. PCB traces, battery internal resistance (10–100 mΩ).
Ohm (Ω) — SI unit. Common resistor values: 100 Ω, 470 Ω, 1 kΩ.
Kilohm (kΩ) — 1,000 Ω. Pull-up resistors, voltage dividers.
Megaohm (MΩ) — 1,000,000 Ω. Insulation resistance, high-impedance circuits.
Gigaohm (GΩ) — 10⁹ Ω. MOSFET gate leakage, ESD protection.

Ohm's Law

V = I × R | I = V / R | R = V / I | P = I² × R = V² / R

Where V = voltage (V), I = current (A), R = resistance (Ω), P = power (W).

Worked Examples

LED resistor: 470 Ω to kilohms

470 ÷ 1,000 = 0.47 kΩ. A standard LED current-limiting resistor.

Insulation test: 500 MΩ to gigaohms

500 ÷ 1,000 = 0.5 GΩ. Good cable insulation should exceed 100 MΩ.

Battery internal resistance: 100 mΩ to ohms

100 × 0.001 = 0.1 Ω. A car battery has about 10–50 mΩ internal resistance.

Power: 12 V across 100 Ω

P = V² / R = 144 / 100 = 1.44 W. I = V/R = 12/100 = 0.12 A.

Frequently Asked Questions

What is an ohm?

An ohm (Ω) is the SI unit of electrical resistance. A conductor has 1 Ω resistance when 1 volt drives 1 ampere through it.

What is the resistance of human skin?

Dry skin resistance ranges from 1 kΩ to 100 kΩ. Wet or broken skin can drop to 300–1,000 Ω, making electrical shocks much more dangerous.

How do I read resistor color codes?

Each color band represents a digit or multiplier. For a 4-band resistor: bands 1–2 are digits, band 3 is the multiplier (×10ⁿ), band 4 is tolerance (gold = ±5%, silver = ±10%).

Electrical Resistance Converter

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