How this instrument works
Capacitance takes its unit, the farad, from Michael Faraday, formally adopted at an 1881 international electrical congress in Paris. A whole farad is an enormous quantity of charge storage per volt, so nearly every real component is specified in some fraction of one: microfarads (µF, one-millionth of a farad) for electrolytic and larger ceramic parts, nanofarads (nF, one-billionth) for many film and mid-range ceramic capacitors, and picofarads (pF, one-trillionth) for the smallest radio-frequency and timing parts.
Moving between those prefixes is pure SI bookkeeping rather than physics: micro means one-millionth (10⁻⁶) and nano means one-billionth (10⁻⁹), so a microfarad is exactly 1,000 nanofarads and a nanofarad is exactly 1,000 picofarads. No component's actual behaviour changes when its value is written 0.1 µF instead of 100 nF — only the digits do, which is exactly why the same 10 nF ceramic disc might appear as '10nF', '.01uF' or '10000pF' across three different manufacturers' datasheets for what is otherwise an identical part.
Surface-mount capacitors compress that same arithmetic onto a component barely larger than a grain of rice using the EIA three-digit code: the first two digits are significant figures and the third is a power-of-ten multiplier in picofarads, so a part marked 104 means 10 × 10⁴ pF, 100,000 pF, which is 100 nF, which is 0.1 µF — three different-looking numbers for one physical value, and exactly the kind of conversion this page exists to make instant.
- Type your value into the Microfarads (uF) field — it opens at 10, a common decoupling or filter capacitor size.
- Read Nanofarads (nF) beneath it; it recalculates on every keystroke, always 1,000 times the microfarad figure.
- Reading an EIA three-digit SMD code instead? Decode it to picofarads first, then divide by 1,000 to reach nanofarads.
- Going backwards, divide your nanofarad figure by 1,000 to recover microfarads.
- Only zero or positive values are accepted, since a capacitance rating cannot run negative.
Worked example — a 10 µF decoupling capacitor in nanofarads
A power-supply design calls for a 10 µF electrolytic capacitor across the input rail for bulk decoupling, but the SPICE simulation model built for the board expects every capacitance value entered in nanofarads. Type 10 into Microfarads (uF) and Nanofarads (nF) returns 10000.0 exactly — the same physical part, re-expressed for the simulator's preferred unit.
That figure also makes the part easy to place next to its smaller neighbours on the same rail. A 100 nF ceramic capacitor sitting beside it for high-frequency decoupling is a hundred times smaller in value — 100 nF against 10,000 nF — which is exactly the split most power-supply layouts use: a large electrolytic for bulk energy storage, paired with a small ceramic for fast transient response.
Questions
Is converting microfarads to nanofarads a measurement, or just arithmetic?
Pure arithmetic. Micro and nano are both fixed SI decimal prefixes — 10⁻⁶ and 10⁻⁹ respectively — so a microfarad is exactly 1,000 nanofarads by definition, with no physical measurement, tolerance or rounding involved. The only real-world uncertainty in a capacitor's actual value comes from the part's own manufacturing tolerance, commonly ±5%, ±10% or ±20%, which this conversion has nothing to do with.
How do I decode a three-digit SMD capacitor marking like 104 or 223?
Read the first two digits as significant figures and the third as a power-of-ten multiplier, all in picofarads. So 104 means 10 × 10⁴ pF = 100,000 pF = 100 nF = 0.1 µF, and 223 means 22 × 10³ pF = 22,000 pF = 22 nF = 0.022 µF. Once you have the picofarad figure, divide by 1,000 for nanofarads or by 1,000,000 for microfarads.
Why do different capacitor datasheets use different unit prefixes for what looks like the same part?
Because there is no single house style across manufacturers, and older parts inherited conventions from print-friendly labelling. A 100 nF ceramic disc might be marked '.1' meaning 0.1 µF, '100n', or '104' depending on the maker and the era, and larger electrolytics almost always default to microfarads simply because their values are too big to comfortably write in nanofarads or picofarads.
Why is the farad itself so rarely used directly in electronics?
Because one whole farad is an impractically large amount of capacitance for almost any conventional component — parallel plates a millimetre apart in air would need dozens of square kilometres of area to reach it. Only supercapacitors, built on a nanometre-scale electrochemical double layer rather than simple plates, reach whole farads; everything else in ordinary electronics lives in the microfarad-and-below range this converter covers.
Does converting between microfarads and nanofarads affect a capacitor's voltage rating or tolerance?
No — this conversion only rewrites the capacitance figure itself in a different SI prefix. Voltage rating, tolerance, dielectric type (such as ceramic X7R or C0G, film, or electrolytic) and temperature coefficient are all separate specifications on the same datasheet line, and none of them are touched by moving a decimal point between microfarads and nanofarads.
How do timing and filter circuits typically split between microfarads and nanofarads?
Roughly by frequency and role. Bulk power-supply filtering and audio coupling capacitors usually sit in the microfarad range; RC timing networks for oscillators, filters and debounce circuits running in the kilohertz-to-megahertz range commonly land in nanofarads; and radio-frequency tuning and bypass capacitors drop further still, into picofarads. This converter's default of 10 µF sits solidly in the bulk-filtering range.
Can this converter handle very small fractional microfarad values, like 0.001 µF?
Yes — 0.001 µF converts to exactly 1 nF, which is also written 1000 pF, and is a genuinely common ceramic capacitor value. Enter any nonnegative figure, including small decimals, and the ×1000 factor applies identically whether the input represents a bulk electrolytic or the smallest ceramic disc on a board.