Current Converter

Datasheets and lab notes don't agree on units. One reference gives a sensor's draw in microamperes, another in milliamperes, and the calculation you actually need is in amps. Converting in your head means counting decimal places and hoping you got the direction right.

Enter a value in any of the three fields — A, mA, or μA — and the other two update. The conversion factors are simple powers of ten (1 A = 1000 mA = 1,000,000 μA), but visual confirmation that you didn't slip a digit is worth the half second of friction it removes from electronics work.

Mostly used during low-power circuit design, where leakage currents in nanoamps and operating currents in tens of milliamps share the same schematic and the units have to line up before any arithmetic makes sense.

The arithmetic is trivial — three units related by powers of ten — but the failure mode isn't arithmetic. It's keeping units consistent across a circuit. A microcontroller datasheet quotes idle current in microamps, active current in milliamps, and peak current in amps; if you mix them while computing battery life you'll be off by orders of magnitude in either direction, and you won't notice until the prototype runs the battery dry overnight or the LED looks unusually dim. The converter exists to remove the half-second of mental friction that makes those errors slip in.

Worked example: a sensor draws 2.4 μA at idle and 18 mA when transmitting, transmitting once per minute for 50 ms. Average current = (idle current × idle fraction) + (active current × active fraction). Idle fraction = 11.95 / 12 = 0.9958, active fraction = 0.05 / 12 = 0.00417 over each 12-second cycle (or scale to one minute). Compute it in microamps everywhere: 2.4 × 0.9958 + 18000 × 0.00417 ≈ 77 μA average. A 1000 mAh battery (= 1,000,000 μAh) lasts 1,000,000 / 77 ≈ 13,000 hours, or about 18 months. Get a unit wrong and you'd report 18 days or 1,800 years.

What the converter cannot do is help with AC versus DC distinctions, RMS versus peak, or current direction in a circuit. Those are the failure modes that actually bite engineers. AC current of 2 A "RMS" is not the same quantity as peak 2 A, and conflating them in a power calculation undersizes or oversizes components. The converter does unit scaling only; circuit analysis is the next layer up.

For very small currents (below about 100 nA), measurement itself becomes the limit — most multimeters can't reliably read below microamps, and parasitic leakage in your test fixture can dominate the reading. If the calculation says you need to verify nanoamp-scale values, the right next step is a Keithley source-measure unit, not a converter.