Electrical Unit Converter (V, A, Ω)
Convert voltage, current and resistance across their SI-prefixed scales (nano to mega) — pick a quantity, type a value, see every scale at once.
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How It Works
Pick the quantity you're converting — voltage, current, or resistance — type a number in any SI-prefixed scale, and the tool instantly recalculates that same value across the full prefix ladder for that quantity: nano (n, ×10⁻⁹), micro (µ, ×10⁻⁶), milli (m, ×10⁻³), the base unit, kilo (k, ×10³), and mega (M, ×10⁶). Each step up or down the ladder is a factor of 1,000, so a resistor marked 4,700 Ω reads as 4.7 kΩ on a color-band chart, or 4,700,000 mΩ if you ever needed the milliohm figure — all three numbers describe the exact same physical resistance, just expressed at different scales.
This is deliberately a one-quantity converter: it moves a voltage value between mV, V and kV, or a current value between µA, mA and A, or a resistance value between mΩ, Ω, kΩ and MΩ. It does not relate the three quantities to each other. Circuit relationships — how a given voltage across a given resistance determines the current, per V = I × R — belong to this site's separate Ohm's Law calculator, a deliberately different tool with a different job. Conflating the two is the single most common misunderstanding: someone types a resistance value here expecting a current or voltage to appear, and nothing does, because that math isn't what a prefix converter performs.
What to Know
- Voltage (V): everyday scales run from millivolts (sensor and audio signal levels, mV) through volts (batteries, mains-adjacent electronics) up to kilovolts (kV, power transmission, X-ray tubes) and occasionally megavolts (MV, particle accelerators, lightning).
- Current (A): microamps (µA) show up in sleep-mode electronics and biosignals, milliamps (mA) in LEDs and small motors, amps (A) in household circuits, and kiloamps (kA) in short-circuit fault currents and lightning strikes.
- Resistance (Ω): milliohms (mΩ) describe wire and contact resistance, ohms (Ω) cover most resistors and component specs, kilohms (kΩ) and megohms (MΩ) appear on pull-up resistors, potentiometers, and insulation-resistance tests.
- Reading resistor codes: a datasheet or color-band chart might quote "4k7" (common shorthand for 4.7 kΩ, chosen to avoid a decimal point that could smudge or be misread) — this tool confirms that 4k7 is 4,700 Ω, or 4,700,000 mΩ, letting you cross-check by hand.
- Precision at extremes: converting a tiny resistance (like 0.05 Ω, a fuse or shunt resistor) up to megohms produces a very small decimal; converting a large one (10 MΩ, a high-voltage bleeder) down to milliohms produces a huge integer. Both are exact — SI prefixes are always powers of ten, never approximations.
Frequently Asked Questions
Why doesn't this also compute V=IR?
This is a pure unit-scale converter — it moves one quantity (say, resistance) between nano, micro, milli, kilo and mega scales, all describing the same physical value. It never combines two different quantities into a third. For that, use this site's dedicated Ohm's Law calculator, built specifically to compute voltage, current or resistance from the other two.
What's the actual difference between this converter and the Ohm's Law calculator?
This tool answers "what is 4700 Ω in kΩ" — a scale change within one quantity. The Ohm's Law calculator answers "what current flows through 4700 Ω at 12 V" — a relationship between three different quantities. They share no math and serve different questions, even though both live under the electrical tools on this site.
Why do engineers write "4k7" instead of "4.7 kΩ" or "4700"?
On a printed circuit board silkscreen or a photocopied datasheet, a decimal point can smudge, wear off, or get misread as dirt — "4k7" embeds the unit prefix where the decimal point would go, so the value survives poor print quality. This tool shows the same figure as 4.7 kΩ, 4700 Ω or 4,700,000 mΩ so you can match whichever notation you're reading.
Do these SI prefixes only apply to volts, amps and ohms?
No — nano, micro, milli, kilo and mega are part of the general SI prefix system and apply the same way to any unit: nanoseconds, microfarads, milliliters, kilograms, megabytes. This tool restricts itself to voltage, current and resistance because those are the three quantities electricians and hobbyists convert most often side by side.
How accurate are the converted values?
Conversions are exact multiplications or divisions by powers of ten (1,000 per full prefix step), performed with standard floating-point arithmetic in your browser. The only limits are floating-point display precision at very large or very small magnitudes — the underlying math introduces no rounding error of its own.
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Electrical Unit Converter (V, A, Ω)
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