Current Converter
This converter changes a measurement of electrical current from any one unit into all the others at once. Current is measured in amperes, the SI base unit, written A, and in practice you meet it far more often in the smaller units: milliamps for the draw of a microcontroller or an LED, microamps for the sleep current of a battery-powered sensor, and nanoamps for leakage in a high-impedance circuit. The relationships are all powers of ten, which sounds simple until you are reading a datasheet at the end of a long day and the figure is written as 0.00047 A rather than 470 uA. That is where mistakes happen, and where a converter earns its place. Enter a value in whichever unit you have it in and every other unit updates immediately, so you can check a datasheet figure against a multimeter reading without moving a decimal point by hand. All the factors here are exact by definition rather than rounded, because the prefixes are defined by the SI system: milli is one thousandth, micro is one millionth, nano is one billionth, and kilo is one thousand. The converter also shows the value in scientific notation, which is usually how a datasheet will print very small currents, and it works for negative values, since current has direction as well as magnitude.
The prefixes are exact by SI definition, so no rounding is introduced by the conversion itself. Very large or very small results switch to scientific notation.
How it works
Every unit is converted to amperes first, then out to the target unit. The factors are exact: 1 kA is 1,000 A, 1 mA is 0.001 A, 1 uA is 0.000001 A and 1 nA is 0.000000001 A. Because these are powers of ten defined by the SI prefix system rather than measured ratios, converting between them introduces no error at all. The only rounding you will see is in the display, where results beyond about fifteen significant figures are shown in scientific notation.
Worked example
Take the default of 1 ampere. In milliamps that is 1 x 1,000 = 1,000 mA. In microamps it is 1 x 1,000,000 = 1,000,000 uA, and in nanoamps 1 x 1,000,000,000 nA. Going the other way, 1 A is 0.001 kA. A more realistic case: a sensor datasheet quotes a sleep current of 0.00047 A. Entered as amperes, that reads 0.47 mA or 470 uA, which is the figure you would actually compare against a budget for battery life.
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