Resistance Converter

Resistance unit converter for ohms, kiloohms, megaohms, and more

If you are reading a resistor value, checking a multimeter reading, or copying specs from a datasheet, the unit is often the part that causes mistakes. A value like 4.7 can mean 4.7 Ω, 4.7 kΩ, or 4.7 MΩ, and those are separated by factors of one thousand. This resistance converter is built for the most common real-world decision: you have a resistance value in one unit and you need the same value in another unit without doing mental scaling or risking a unit slip. It converts between milliohms (mΩ), ohms (Ω), kiloohms (kΩ), megaohms (MΩ), and gigaohms (GΩ).

To use it, enter the resistance value as you have it (decimals are fine), select the unit you currently have, then either choose a target unit or leave the converter on “Show all common units.” The “Show all” option is the default because it matches how people actually work: you might not know which unit the other tool or document expects, so seeing the full table lets you pick the right one immediately. The results are all derived from the same base conversion: everything is converted to ohms internally, then scaled to the output units. This keeps the conversions consistent and avoids rounding drift from converting unit to unit multiple times.

The output is designed to be scannable and decision-focused. You get a primary line that states what your input equals, followed by a short table that lists the same resistance across the common units. This is useful when you are comparing components (for example, confirming that a “4700 Ω” resistor is the same as “4.7 kΩ”), when validating measurement ranges (for example, whether your reading is closer to mΩ or Ω for low-resistance conductors), or when translating manufacturer specs that mix unit conventions. If you need higher precision than two decimals, treat the output as a quick converter and keep your source value at full precision in your own notes or measurement record.

Assumptions and how to use this calculator

• This converter treats resistance as a pure unit conversion problem (it does not model temperature, tolerance, or frequency effects).
• Values are converted using standard SI scaling: 1 kΩ = 1,000 Ω, 1 MΩ = 1,000,000 Ω, 1 GΩ = 1,000,000,000 Ω, and 1 mΩ = 0.001 Ω.
• Inputs must be greater than 0. If you truly need to represent 0 Ω (a short), this tool is not meant for circuit fault modelling.
• Results are displayed to two decimals for readability. Keep your original value if you require more significant figures.
• Unit selection is limited to the most common resistance units used in electronics and measurement; it intentionally excludes less common variants.

Common questions

What is the difference between Ω, kΩ, and MΩ?

They are the same measurement in different scales. Ω is the base unit. kΩ means thousands of ohms, and MΩ means millions of ohms. Converting between them is a scaling move, not a different type of resistance.

Why does my resistor say “4K7” or “R47” instead of a normal number?

Those are common resistor markings where the letter replaces the decimal point. For example, 4K7 means 4.7 kΩ and R47 means 0.47 Ω. This converter expects a normal number and a unit, so you would enter 4.7 and choose kΩ, or enter 0.47 and choose Ω.

When would I use milliohms (mΩ)?

Milliohms are common for very low resistance measurements, such as battery internal resistance, bus bars, shunts, or heavy-gauge conductors. If your value is under about 1 Ω, mΩ can make the number easier to read without leading zeros.

My multimeter shows “0.00” or changes around. Is the converter wrong?

No. This tool only converts the number you enter. If the reading itself is unstable, the issue is typically measurement resolution, probe contact resistance, lead resistance, or a changing load. Enter your best stable reading and convert that.

Does this converter tell me resistor wattage, tolerance, or which resistor to buy?

No. It is unit conversion only. Wattage and tolerance depend on the circuit, voltage/current, and component ratings. Use this tool to translate resistance values cleanly, then choose parts based on your design requirements.