The difference is not accuracy — it is whether the circuit has to be broken.
Measuring current with a multimeter
The meter goes in series, so the circuit must be opened and the meter inserted into it. On a bench that is fine. On an installation it means disconnecting a live conductor, which is exactly what you were trying to avoid.
It is also the configuration that destroys meters, because a meter left on the current range and then placed across a supply is a near short circuit.
Measuring current with a clamp
The jaw goes around one conductor and reads the magnetic field. Nothing is disconnected and nothing is inserted. That is the entire argument, and it is a large one.
What a clamp gives up
Resolution at low currents, on most models. A general clamp resolves tenths of an amp, which is useless for a twenty-milliamp leakage — for that you need a clamp specified in milliamps, and one we compare resolves to 1 mA.
What to check before buying
Whether it reads DC as well as AC, and the jaw opening — which decides whether it fits your cable, and which most listings do not state.
What gets asked here
Can a clamp meter replace a multimeter?
Most clamps include multimeter functions, so for many people yes. Voltage and resistance measurement on a clamp is usually adequate.
Why does my clamp read zero on the flex?
Because you clamped both conductors. Their fields cancel — clamp one conductor only.
Last reviewed 31 August 2026