Resistance Converter
Convert Ohms, Kiloohms, Megaohms, and more.
Typical Resistance Values
| Component / Material | Resistance | Application |
|---|---|---|
| Copper Wire (1m) | ~0.02 Ω | Conductor |
| Human Skin (Dry) | ~100,000 Ω (100 kΩ) | Insulator (Variable) |
| Standard Resistors | 1 kΩ, 10 kΩ | Electronics |
| Insulation Material | ~1,000 MΩ+ | Safety |
What is Resistance?
Electrical resistance is a measure of the opposition to the flow of electric current. It is analogous to friction in mechanical systems.
Unit Explanations
Ohm (Ω)
The SI unit of electrical resistance, named after Georg Simon Ohm.
Kiloohm (kΩ)
One thousand ohms. Very common value in electronic circuits (e.g., used for pull-up resistors).
Megaohm (MΩ)
One million ohms. Used in insulation resistance testing and high-impedance inputs.
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The Gatekeeper of Current
Electrical Resistance is the property of a material that opposes the flow of electric current. It is the friction of the electrical world. Without resistance, circuits would short out instantly, batteries would explode, and electronics would fry.
Whether you are calculating the correct resistor for an LED, checking the insulation of a motor winding, or designing a precision sensor circuit, accurate conversion between Ohms, Kiloohms, and Megaohms is critical.
Understanding the Ohm (Ω)
The Ohm (symbol: Ω) is the SI unit of resistance, named after Georg Ohm. It is defined as standard:
This relationship is the core of Ohm's Law (V = I × R).
Common Unit Prefixes
Resistance in Application
Resistance values vary wildly across different materials and components:
Certain materials at very low temperatures conduct with zero resistance.
Standard wires have very low resistance to minimize power loss.
Dry skin has high resistance; wet or broken skin drops to ~1kΩ (dangerous).
Carbon or film resistors used to control current in circuits.
Ultra-pure water is an insulator! Tap water conducts due to dissolved ions.
Air is an excellent insulator until voltage breaks it down (lightning).
🔥 Why Resistance Causes Heat
When electrons force their way through a resistive material, they collide with atoms, transferring kinetic energy into heat. This is known as Joule Heating.
This effect is useful in toasters, electric heaters, and incandescent bulbs (where resistance creates light). However, in computers and power lines, this heat represents wasted energy and must be minimized.
Frequently Asked Questions
What is Electrical Resistance?
Resistance is a measure of the opposition to current flow in an electrical circuit. Think of it like a narrow section in a water pipe: the narrower the pipe, the harder it is for water to flow. Similarly, higher resistance reduces the flow of electrons (current) for a given voltage.
What is the difference between Resistance and Impedance?
Resistance (R) applies to DC circuits and opposes the flow of steady current. Impedance (Z) applies to AC circuits and includes both resistance and reactance (opposition from capacitors and inductors). For simple resistors, resistance and impedance are the same, but for complex AC circuits, they are very different.
How do I convert Kiloohms (kΩ) to Ohms (Ω)?
The prefix 'Kilo' means 1,000. Therefore, 1 kΩ = 1,000 Ω. To convert kiloohms to ohms, multiply by 1,000. To convert ohms to kiloohms, divide by 1,000. For example, a 4.7 kΩ resistor is 4,700 Ω.
What is Ohm's Law?
Ohm's Law states that V = I × R (Voltage = Current × Resistance). Solving for Resistance gives R = V / I. This means resistance is the ratio of voltage across a component to the current flowing through it. It is the most fundamental formula in electronics.
What is a 0 Ohm resistor?
A 0 Ohm resistor (or 'jumper') is a wire link packaged like a resistor. It is used in automated manufacturing (pick-and-place machines) to bridge two traces on a PCB, acting like a switch or a configuration option.
Why do we measure Insulation Resistance (MΩ)?
Insulation resistance tests (using a 'Megger') check if the insulation on wires is intact. Good insulation should have very high resistance (Megaohms or Gigaohms). If the resistance drops, it means current is leaking, usually due to moisture, heat damage, or aging, which can cause shocks or fires.
What affects the resistance of a wire?
Four main factors affect wire resistance: Material (copper conducts better than aluminum), Length (longer wires have more resistance), Cross-sectional Area (thicker wires have less resistance), and Temperature (resistance typically increases with temperature).
What are standard resistor values (E12/E24)?
Resistors aren't made in every possible value. They use standard logarithmic series. The E12 series (10% tolerance) has 12 values per decade (e.g., 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82). The E24 series (5% tolerance) adds more intermediate values.
What is Conductance?
Conductance (G) is the inverse of resistance (G = 1/R). It measures how easy it is for current to flow. The unit of conductance is the Siemens (S) (formerly called the Mho - 'Ohm' spelled backward!).
How do resistors behave in Series vs. Parallel?
In Series, resistances add up directly (R_total = R1 + R2...). In Parallel, the total resistance decreases (1/R_total = 1/R1 + 1/R2...). Two equal resistors in parallel have half the resistance of one.