Resistance Converter

Convert between ohms, kilohms, megohms, and milliohms — for electronics, circuit design, and electrical testing.

Resistance

Ω, kΩ, MΩ

From

Result

1000

1 Ω = 1000 mΩ

Popular conversions

What Is a Resistance Converter?

A resistance converter translates electrical resistance between prefixes — ohms to kilohms, megohms to ohms, milliohms to ohms. Resistance is how strongly a component opposes the flow of current, and the SI unit is the ohm (Ω). Resistor values span an enormous range, from the milliohms of a shunt or wire to the megohms of insulation and high-impedance inputs, all handled with metric prefixes.

This converter routes through the ohm using exact power-of-ten prefixes. Resistance ties into Ohm's law (R = V/I) and combines in series and parallel, so reading a value in the right prefix is essential for circuit design and testing. Enter a value in any prefix and see it across milliohms, ohms, kilohms, and megohms.

This is one category of the full Unit Converter — pair it with our percentage calculator or scientific calculator for related everyday maths.

How Resistance Conversion Works

Everything routes through the ohm

Each prefix has a fixed power-of-ten link to the ohm. The converter normalises to ohms, then projects to every other prefix.

Metric prefixes scale by 1,000

1 kΩ = 1,000 Ω; 1 MΩ = 1,000 kΩ; 1 Ω = 1,000 mΩ. Each step shifts the decimal point three places.

Resistance in Ohm's law

R = V/I. A given resistance sets how much current a voltage drives — the core of every circuit calculation.

Series adds, parallel divides

Resistors in series add directly; in parallel the reciprocals add. The conversion handles units; the combination is separate.

Core Resistance Conversion Factors

Each step is a power of ten. Multiply to reach ohms; divide to come back.

kΩ → Ω

× 1000

One kilohm is 1,000 ohms. Common resistor values live in the kilohm range.

MΩ → kΩ

× 1000

One megohm is 1,000 kilohms, used for high-impedance and insulation values.

Ohm's law

R = V / I

Resistance equals voltage divided by current — the link to voltage and current.

How to Use the Resistance Converter

1
Enter the resistance value
Type the resistance you want to convert — a resistor value, a measured reading, an insulation spec.
2
Choose the 'from' unit
Pick ohms, kilohms, megohms, or milliohms as your starting prefix.
3
Choose the 'to' unit
Select the target prefix, or swap the two to reverse direction.
4
Read every prefix at once
The all-units table shows the resistance across mΩ, Ω, kΩ, and MΩ together.

Key Resistance Concepts

Ohm

The SI unit of resistance: the resistance that lets one ampere flow under one volt. Named after Georg Ohm, whose law underpins circuit analysis.

Kilohm and megohm

1 kΩ = 1,000 Ω; 1 MΩ = 1,000,000 Ω. Most signal-circuit resistors are in the kilohm-to-megohm range.

Milliohm

0.001 Ω. Shunts, contacts, and wire resistance are measured in milliohms, where even tiny values matter for current sensing.

Series and parallel

Series resistances add; parallel resistances combine as reciprocals. Converting units is the first step before combining them.

Real-World Resistance Conversions

🎛️

Resistor values

A 4.7 kΩ resistor is 4,700 Ω; a 1 MΩ resistor is 1,000,000 Ω. Colour codes and specs use kΩ and MΩ.

🔌

Wire resistance

A length of wire might be 50 mΩ (0.05 Ω). Low resistances are quoted in milliohms for power and current-sensing work.

🩹

Body resistance

Dry human skin is around 100 kΩ; wet skin far less. Safety analysis converts between kΩ and Ω to estimate shock current.

🔬

Insulation testing

Good insulation reads many megohms. Insulation testers (meggers) report MΩ to confirm wiring integrity.

📟

Pull-up resistors

A 10 kΩ pull-up is 10,000 Ω. Digital circuits use kilohm pull-ups and pull-downs throughout.

🔋

Internal resistance

A battery's internal resistance might be 100 mΩ. Milliohm-scale values determine how much current a cell can deliver.

Best Practices for Resistance Conversion

✓Carry the prefix carefully. kΩ and Ω differ by 1,000; MΩ and kΩ by 1,000. A dropped prefix mis-sizes a resistor or misreads a measurement drastically.
✓Convert before combining. To add series or parallel resistances, put them all in the same unit first. Mixing kΩ and Ω in a sum is a common slip.
✓Use Ohm's law to verify. R = V/I lets you check a resistance against a circuit's voltage and current. A wildly off value usually signals a prefix error.
✓Use milliohms for low values. Shunts, contacts, and wire are sub-ohm. Milliohms keep these small but important resistances readable.
✓Mind tolerance and temperature. Real resistors vary with tolerance (±1%, ±5%) and temperature. The converted value is nominal, not the exact in-circuit resistance.

Common Resistance Conversion Mistakes

Dropping a metric prefix

Reading kΩ as Ω, or MΩ as kΩ, shifts resistance 1,000-fold — enough to badly miscalculate circuit current.

Combining mixed units

Adding a 4.7 kΩ and a 470 Ω resistor requires the same unit first. Summing 4.7 and 470 directly is wrong by a factor of ten.

Confusing resistance with conductance

Conductance (siemens) is the reciprocal of resistance. They're inversely related, not a simple prefix change.

Ignoring tolerance

A '10 kΩ ±5%' resistor is anywhere from 9.5 to 10.5 kΩ. The converted nominal value isn't the exact in-circuit resistance.

Why Resistance Conversion Matters

Resistance sets the current in every circuit, the behaviour of sensors and dividers, and the integrity of insulation — and it spans milliohms to megohms, all expressed with metric prefixes. A prefix slip can mean designing with a resistor 1,000 times the intended value, miscalculating shock current, or misreading an insulation test.

Because resistance is central to Ohm's law and to series/parallel combinations, accurate units keep circuit design and electrical testing reliable. A converter that routes through the ohm and exposes mΩ, Ω, kΩ, and MΩ together lets designers, technicians, and students read and combine resistance values at the correct scale.

Built for electronics designers, electricians, test technicians, and students converting between ohms, kilohms, and megohms.

Linear unit factors follow the BIPM SI brochure, the NIST Guide to the SI, and ISO 80000. Currency rates load live from open.er-api.com; crypto prices from CoinGecko. See our methodology and editorial policy. Educational only — not certified for regulated trading, settlement, medical, or aerospace use.

Resistance Converter FAQs

Multiply kilohms by 1,000 to get ohms, since one kilohm is 1,000 Ω. So a 4.7 kΩ resistor is 4,700 Ω, and a 1 MΩ resistor is 1,000,000 Ω. To go from ohms to milliohms, multiply by 1,000 (1 Ω = 1,000 mΩ).

The ohm (Ω) is the SI unit of electrical resistance, defined as the resistance that allows one ampere of current to flow when one volt is applied across it. It's named after Georg Ohm, whose law, V = I × R, relates voltage, current, and resistance.

In series, resistances add directly: R = R₁ + R₂ + …. In parallel, the reciprocals add: 1/R = 1/R₁ + 1/R₂ + …. Always convert all values to the same unit (e.g. ohms) before combining — mixing kΩ and Ω in the arithmetic is a common error.

They're reciprocals. Resistance (ohms) measures opposition to current; conductance (siemens) measures how easily current flows, and equals 1 ÷ resistance. A 10 Ω resistor has a conductance of 0.1 siemens. Converting between them is an inverse, not a prefix change.

Because very low resistances — wire, contacts, shunts, battery internal resistance — would be awkward fractions of an ohm. Milliohms (0.001 Ω) keep them readable. These small values matter a lot for current sensing and for how much current a source can deliver.

It uses exact metric-prefix definitions (1 kΩ = 1,000 Ω, 1 MΩ = 10⁶ Ω, 1 Ω = 1,000 mΩ) and routes every conversion through the ohm at full precision, so the result is exact to your input precision (the nominal value, before component tolerance).