Best Digital Multimeters
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DMM means digital multimeter: a handheld meter that measures voltage, current, resistance, and often continuity and diodes, with a number on the display. This roundup covers six digital multimeter listings we opened on Amazon on 17 October 2026. Every spec below is what that listing states. Five of the six listings state AC or DC voltage ranges of 600 volts or 1000 volts and current to 10 amps. Three state resistance ranges from 2 MOhm to 60 MOhm. Where a listing’s own wording is ambiguous, we say so.
Quick answer
For household and automotive checks at 600V and below, the Klein Tools MM720 lists the widest set of functions here: auto-ranging TRMS, AC/DC voltage to 1000V, 10A current, 60 MOhm resistance, a low-impedance (LoZ) mode, and CAT IV 600V in its listing. The Klein MM420 covers most of the same ground without LoZ. If you want a Fluke brand with a temperature input included, the Fluke 17B+ is the listing to compare.
A 1000V measurement range is not the same thing as a CAT rating. Read the CAT line in the listing before you choose.
Safety first
The U.S. Occupational Safety and Health Administration states that working with electricity can be dangerous, and that its electrical standards exist to protect workers from hazards such as electric shock, electrocution, fires, and explosions (OSHA, Electrical overview, checked 17 October 2026). Panel, service, or other mains work belongs to a licensed electrician.
How we chose
We kept listings for handheld digital multimeters with a voltage, current, and resistance function. We left out clamp meters, outlet and receptacle testers, and kits where the meter was not the main product. We did not record prices, star ratings, or review counts. The CAT rating shown for each meter is the one its listing states. One listing (AstroAI) does not state a CAT rating in the bullets we read, and we say so.
Comparison table
| Listing | Ranging | Voltage and current (as stated) | CAT (as stated) | Extras stated |
|---|---|---|---|---|
| Klein MM720 | Auto-ranging TRMS | AC/DC to 1000V; 10A AC/DC; 60 MOhm | CAT IV 600V | LoZ mode, temperature, capacitance, frequency/duty cycle, diode |
| Klein MM420 | Auto-ranging TRMS | AC/DC to 600V; 10A AC/DC; 50 MOhm | Lead caps CAT III/CAT IV (listing) | Temperature, capacitance, frequency/duty cycle, diode, 6.6 ft drop |
| Fluke 17B+ | Not stated in the bullets read | AC/DC to 1000V; 10A | CAT III 600V | Temperature to 400 C with type K probe, capacitance, frequency, diode |
| Fluke 15B+ | Not stated in the bullets read | AC/DC to 1000V; 10A | CAT III 600V | Capacitance, diode, dedicated 10A input |
| Klein MM325 | Manual-ranging | AC/DC to 600V; 10A DC; 2 MOhm | CAT III 600V | Lead-alert LEDs, battery test, backlit display |
| AstroAI 6000-count | Auto-ranging, TRMS | 6000 counts; fuses F400mA/600V and F10A/600V | Not stated in the bullets read | Data hold, backlit LCD, auto shut-off, temperature |
Worked example: a 120V outlet check
Take a 120V AC household outlet. Every meter here lists AC voltage up to at least 600V, so a 120 volt reading sits inside the measuring range of all six. A 240 volt circuit also falls within the listed voltage ranges. The choice then comes down to the CAT line for the place you are working, the ranging you prefer, and any extras you need. On current, the Klein MM325 lists 10A DC, while the MM420, MM720, and both Fluke meters list 10A AC/DC. On resistance, the MM325 lists 2 MOhm, the MM420 lists 50 MOhm, and the MM720 lists 60 MOhm. The AstroAI does not state voltage or current ranges in the bullets we read. It lists two ceramic fuses, F400mA/600V and F10A/600V, and says they protect the meter. Read the CAT line and the voltage range as two separate listing facts, and use the meter only for the category the listing states.
The picks and who each one fits
Klein Tools MM720
Best for: a meter that does most electrical and automotive checks and needs LoZ mode to separate ghost voltages from real ones.
Skip if: you only need basic voltage and continuity and want a simpler meter.
The listing states auto-ranging TRMS, AC/DC voltage up to 1000V, 10A AC/DC current, 60 MOhm resistance, LoZ mode, a reverse-contrast LCD, and a CAT IV 600V safety rating. It also includes test lead holders on the back, a kickstand, and an optional magnetic hanger sold separately. Klein MM720 listing on Amazon.
Klein Tools MM420
Best for: a TRMS meter with auto-ranging, a backlit display, and a 6.6 ft drop rating for jobsite use.
Skip if: you need LoZ mode. The listing does not state one.
The listing states auto-ranging TRMS, AC/DC voltage up to 600V, 10A AC/DC current, 50 MOhm resistance, continuity, temperature, capacitance, frequency and duty cycle, and diode test. It says the test leads have CAT III/CAT IV safety caps. The meter’s own CAT rating is not in the bullets we read. Klein MM420 listing on Amazon.
Fluke 17B+
Best for: a Fluke meter that includes a temperature input and a type K probe in one package.
Skip if: you need auto-ranging or LoZ mode. Neither appears in the bullets we read.
The listing states CAT III 600V, AC/DC voltage up to 1000V, 10A current, resistance, continuity, diode, capacitance, frequency, and temperature to 400 degrees Celsius with an included type K thermocouple. The 1000V figure is a measurement range. The CAT rating printed in the listing is CAT III 600V. Fluke 17B+ listing on Amazon.
Fluke 15B+
Best for: a Fluke meter for voltage, current, resistance, continuity, diode, and capacitance without a temperature function.
Skip if: you need temperature measurement. The listing does not state one.
The listing states CAT III 600V, AC/DC voltage up to 1000V, AC/DC current up to 10A, and a dedicated input terminal for current measurements to 10A. Like the 17B+, the 1000V figure is a measurement range and the stated CAT rating is CAT III 600V. Fluke 15B+ listing on Amazon.
Klein Tools MM325
Best for: a manual-ranging meter for basic electrical work, including a battery test mode.
Skip if: you want auto-ranging. The listing describes manual ranging.
The listing states AC/DC voltage up to 600V, 10A DC current, 2 MOhm resistance, continuity, diode test, and battery test. It states CAT III 600V and includes test leads, batteries, and a user manual. Lead-alert LEDs show correct lead placement. Klein MM325 listing on Amazon.
AstroAI 6000-count True RMS
Best for: a low-cost auto-ranging TRMS meter with a backlit display and a stated fuse rating.
Skip if: you need a stated CAT rating for mains work. The bullets we read do not give one.
The listing states 6000 counts, auto-ranging with True RMS for AC current and voltage, a backlit LCD, data hold, auto shut-off, and a kickstand. It lists fuses F400mA/600V and F10A/600V. Check the full listing for a CAT rating before using it on mains. AstroAI 6000-count listing on Amazon.
Common mistakes
- Reading the 1000V measurement range as a CAT rating. The Fluke 17B+ and 15B+ list 1000V measurement and CAT III 600V.
- Assuming a TRMS or auto-ranging meter has a CAT rating. The listings state these functions separately from safety ratings.
- Connecting to a circuit without checking the fuse and input ratings in the listing first.
Who should skip buying a DMM for this job
If you only need to know whether a wire is live, a non-contact tester is a faster tool. A meter gives a number, which helps when you need a value. Anyone working inside a panel should hire a licensed electrician.
Related buying guides
For a wider list of meters, see best hand-held digital multimeter. For auto-ranging models only, see best auto-ranging digital multimeter. For a budget-focused comparison, see best digital volt meter.
FAQ
What is the difference between a CAT rating and a voltage range?
The voltage range is the measurement range the listing states. The CAT rating is a separate line in the listing. The Fluke 17B+ lists 1000V measurement and CAT III 600V, so the two numbers are different, and the draft does not treat one as the other.
Which listings state a CAT rating?
The Klein MM720 (CAT IV 600V), the Klein MM325 (CAT III 600V), the Fluke 17B+ (CAT III 600V), and the Fluke 15B+ (CAT III 600V) state one in the listing. The Klein MM420 states CAT III/CAT IV on its test lead caps. The AstroAI listing does not state a CAT rating in the bullets we read.
Do these meters measure temperature?
The Fluke 17B+ includes a type K thermocouple and measures to 400 C. The Klein MM720, MM420, and the AstroAI list temperature in their features. The Fluke 15B+ and the Klein MM325 do not state temperature.
What does LoZ mode do?
The Klein MM720 lists LoZ mode for identifying ghost or stray voltages. Use the listing’s own description and the manual before relying on it for a decision.
Are auto-ranging meters better?
Auto-ranging picks the measurement range for you. The Klein MM325 is manual-ranging. The other five listings state auto-ranging or do not state a ranging type in the bullets we read.
Bottom line
For the widest stated function set with a CAT IV 600V rating, the Klein MM720 is the listing to compare first. The Fluke 17B+ is the one to choose if temperature and a Fluke brand matter most. Check each listing’s CAT line against your job before you buy.
