Most multimeters can measure capacitance directly if they have a capacitance setting

A multimeter is a handheld tool that measures electrical properties. Many modern multimeters include a capacitance mode — usually marked with the symbol "F" or "µF" on the dial — that lets you read how much electrical charge a capacitor can hold. If your multimeter has this setting, measuring capacitance takes less than a minute and requires no additional equipment.

Not all multimeters have capacitance measurement built in. Older analog multimeters and some budget digital models do not. Check your multimeter's dial or display panel for a capacitance marking. If you do not see one, you have a meter without this feature, and you will need a different approach.

Key Takeaways

  • Turn the dial to the capacitance setting (marked F or µF) and make sure the capacitor is fully discharged before you touch it to the meter probes.
  • Connect the red probe to the positive side of the capacitor and the black probe to the negative side, then read the display — the meter will show the value in microfarads or nanofarads.
  • If the reading shows "1" or stays at zero, the capacitor may be damaged, or you may have the wrong range selected on the dial.
  • Capacitors can hold a dangerous electrical charge even when unplugged, so discharge them safely by touching a screwdriver across both leads before you measure.

Discharge the capacitor safely before you touch it

A capacitor stores electrical energy. Even after power is cut off, it can hold a charge strong enough to damage the meter or injure you. Before you measure, you must release this stored energy.

The safest way is to use an insulated screwdriver. Hold the handle and touch the metal tip across both capacitor leads at the same time. You may see a small spark — that is the capacitor discharging, and it is normal. Wait a few seconds, then touch the leads again to make sure no charge remains. Only after the capacitor is fully discharged should you connect the multimeter probes.

If the capacitor is soldered to a circuit board, you may need to desolder it first. Measuring a capacitor while it is still connected to other components can give a false reading because the meter will measure the combined effect of the capacitor and the surrounding circuit.

Set the multimeter dial to the capacitance range

Locate the capacitance setting on your multimeter dial. It is usually marked with "F" (for farads) or "µF" (for microfarads). Some meters also show "nF" (nanofarads) as a separate range. The dial may have multiple capacitance settings — for example, 2µF, 20µF, 200µF, and 2000µF.

Start with the highest range if you do not know the capacitor's value. If the reading is very small or shows "0.00", turn the dial down to a lower range. The goal is to land on a range where the reading appears in the middle of the display, not at the extreme low or high end. A reading in the middle is more accurate than one at the edges.

Some digital multimeters have an auto-range feature that picks the correct range for you. If your meter has this, look for a button labeled "Auto" or "Range" and press it before you connect the probes.

Connect the probes and read the display

Hold the capacitor so you can see which lead is positive and which is negative. On most capacitors, the negative lead is marked with a stripe or is shorter than the positive lead. If you cannot tell, check the capacitor's label or datasheet.

Touch the red probe to the positive lead and the black probe to the negative lead. Keep the probes in place for a few seconds — the meter needs time to measure and display the value. Do not move the probes or touch the capacitor leads with your fingers while the meter is reading, because your body can interfere with the measurement.

The display will show a number followed by a unit: µF (microfarads), nF (nanofarads), or pF (picofarads). Write down this value. If you are checking whether a capacitor is good or bad, compare the reading to the value printed on the capacitor's body. A reading within 10 to 20 percent of the marked value usually means the capacitor is working.

Understand what the readings mean

A normal reading falls close to the value marked on the capacitor. For example, a capacitor labeled "10µF" should read somewhere between 8µF and 12µF. Small variations are expected and do not mean the capacitor is faulty.

A reading of "1" or "OL" (overload) usually means the capacitor is damaged or the range is set too low. Try switching to a higher range on the dial. If the reading is still "1" or "OL" after you try the highest range, the capacitor is likely bad and should be replaced.

A reading of "0.00" or very close to zero can mean the capacitor is shorted (internally broken) or the range is set too high. Move down to a lower range and try again. If the reading stays at zero across multiple ranges, the capacitor is probably faulty.

Troubleshoot common measurement problems

If the meter shows a wildly different value than what is printed on the capacitor, first check that you have the right range selected. A capacitor marked "100µF" will show as "0.10" if you are reading it on the nanofarad range instead of the microfarad range — the value is the same, just displayed in different units.

If the reading bounces or changes every time you measure, the capacitor may be partially damaged or the probes may not be making solid contact with the leads. Clean the capacitor leads with a dry cloth and try again. If the reading is still unstable, the capacitor is likely failing.

If your multimeter shows "1" on every capacitor you test, even ones you know are good, the capacitance setting may be broken or the probes may be damaged. Try measuring a known-good capacitor from a working device. If that also shows "1", the meter needs repair or replacement.

What to do if your multimeter does not have a capacitance setting

Older analog multimeters and some inexpensive digital models do not include capacitance measurement. If your meter does not have a capacitance dial setting, you have a few options.

The simplest is to buy a multimeter that does have capacitance measurement. A basic digital multimeter with capacitance costs between $20 and $50 and will last for years. If you only need to check capacitance once or twice, borrowing a meter from a friend or local electronics club may be faster than buying one.

If you have access to an oscilloscope or a dedicated capacitance meter, those tools can also measure capacitance. An oscilloscope is more expensive and requires more skill to use, but it gives very precise readings. A dedicated capacitance meter is simpler but less common in home workshops.

Frequently Asked Questions

Can I measure a capacitor while it is still soldered to a circuit board?

You can try, but the reading will usually be inaccurate because the meter measures the capacitor and all the surrounding components together. Desoldering the capacitor first gives you a true reading of just that part. If desoldering is not practical, a reading that is close to the marked value usually means the capacitor is working.

What does it mean if the multimeter shows a very high reading, like 50µF when the capacitor says 10µF?

The capacitor is likely damaged or leaking internally. A capacitor that reads significantly higher than its marked value is failing and should be replaced. A small difference — within 10 to 20 percent — is normal, but anything larger suggests a problem.

Do I need to remove the capacitor from the circuit to measure it safely?

Yes. Measuring a capacitor while it is soldered in place can damage the meter or give a false reading. Always desolder the capacitor first, discharge it with a screwdriver, and then connect the multimeter probes. This protects both you and the meter.

Why does my multimeter show different readings each time I measure the same capacitor?

Unstable readings usually mean the probes are not making firm contact with the capacitor leads, or the capacitor is partially damaged. Clean the leads with a dry cloth, make sure the probes are pressed firmly against them, and try again. If readings still bounce around, the capacitor is likely failing.

Can a capacitor be too small to measure with a multimeter?

Yes. Very small capacitors — in the picofarad range — are at the edge of what most multimeters can measure accurately. If your meter has a pF range, you can try it, but the reading may not be reliable. For very precise measurement of tiny capacitors, a dedicated capacitance meter or an oscilloscope is better.