Klein MM300 vs MM400 Comparison and In-depth Reviews 2024

Multimeters are indispensable tools for electricians, technicians, and DIY enthusiasts alike. They help us measure voltage, current, resistance, and more, making them a vital component of any toolbox. Two popular options in the world of multimeters are the Klein Tools MM300 and MM400. We'll delve into the klein mm300 vs mm400 to help you make an informed decision.

Klein Tools MM300 vs Klein MM400

Klein Tools MM300 Multimeter Reviews

“Best for Digital Manual-Ranging”

The Klein Tools MM300 Multimeter is your go-to solution for a wide range of applications in residential, business, and light-industrial environments. This compact and durable multimeter offers accurate measurements for various electrical tasks, ensuring you have the right tool for the job. 

Klein MM300 vs MM400

With its easy-to-read LCD screen and straightforward dial, you can effortlessly measure voltage, and current. The MM300's digital manual-ranging feature offers the chance to choose the settings and select the appropriate measurement range, saving you time and effort. 

Its sturdy construction is built to withstand everyday wear and tear, making it a long-lasting companion in your toolkit. Whether you're working on household wiring, automotive repairs, or industrial applications, this multimeter provides consistent and precise results. 


Voltage MeasurementThe MM300 can measure voltage levels of up to 600V AC/DC, making it suitable for various electrical tasks.

Current Measurement: It allows for the measurement of 10A DC current, essential for troubleshooting circuits.

Resistance Measurement: With a 2MOhms resistance range, it's adept at checking continuity and resistance in circuits.

Voltage Tester: This multimeter also functions as a voltage tester for batteries, diodes, and continuity.

Durability: Designed to endure the rigors of the job site, the MM300 can withstand a 3.3-foot drop and daily wear and tear.

Safety Rating: It boasts a CAT III 600V safety rating, ensuring your safety when working with electrical systems.

Battery IndicatorThe low battery indicator lets you know when it's time to replace the batteries, and the easily accessible battery compartment simplifies battery changes.

Accessories: It comes with test leads, batteries, and a user manual, making it ready for immediate use.

  • User-friendly
  • 3.3-foot drop resistance
  • Frequency measurement
  • Low battery indicator
  • Lacks some advanced features like temperature measurement

What’s In The Package

  • Test leads
  • Batteries
  • User manual

Klein Tools MM400 Multimeter Reviews

“Best for CAT III 600V Safety Rating”

 Klein Tools MM400 Multimeter stands out with its low battery indicator, ensuring you're never caught off guard during crucial tasks. Its easily accessible battery compartment simplifies replacement, ensuring uninterrupted workflow. It is renowned for its exceptional CAT III 600V safety rating.

Klein MM300 vs MM400

Precision and efficiency are at the core of this multimeter's design, making it ideal for professionals and DIY enthusiasts alike. Whether you're measuring voltage, current, or resistance, the MM400 delivers accurate results every time. 

Its user-friendly interface and sturdy construction enhance usability and durability, making it a trustworthy choice for various applications.


Expanded Measurement Capability: The MM400 offers a broader range of measurement options, including 10A AC/DC current and 40M Ohms resistance.

Temperature Measurement: It can measure temperature, making it useful for HVAC and other temperature-sensitive applications.

Additional Electrical Testing: The MM400 can measure capacitance, frequency, duty-cycle, and test diodes and continuity, making it more versatile.

Safety Rating: Like the MM300, it carries a CAT III 600V safety rating, ensuring safe usage.

Durability: Built to withstand a 3.3-foot drop and daily job site use, it's as robust as the MM300.

Battery Indicator: The low battery indicator and accessible battery compartment are convenient features for maintaining the tool.

Accessories: In addition to test leads, the MM400 includes a thermocouple with an adapter, further enhancing its versatility.

  • Temperature measurement
  • More budget-friendly than MM300
  • Thermocouple for temperature measurements
  • CAT III 600V safety
  • Its extensive features may be overwhelming for beginners

What’s In The Package

  • Test leads
  • Thermocouple with adapter
  • Batteries
  • User manual

Similarities and Differences (Klein MM300 vs MM400)

When you're picking a multimeter for your electrical tasks, it's important to understand the differences between your options. Two popular multimeters on the market are the klein mm300 vs mm400. They are both good at what they do, but they have some unique features. In this comparison, we'll look at how they are similar and what sets them apart, so you can make the right choice.


1. Voltage Measurement

Both the klein mm300 vs mm400 multimeters can measure voltage up to 600V AC/DC. This means they can help you with many electrical jobs, whether you're fixing something at home or working on a project.

2. Durability

These multimeters are tough. They can handle being dropped from about 3.3 feet (1 meter) without getting damaged. So, if you're a bit clumsy or work in a busy environment, these multimeters can take the heat.

3. Safety Rating

Both the MM300 and MM400 have a safety rating of CAT III 600V. This means they're safe to use in places like homes, businesses, and light industries. Safety is a big deal when dealing with electricity, so it's good to know that these tools have your back.

4. Battery Indicator

You don't want your multimeter to run out of battery in the middle of a job. That's why both models have a little warning light that tells you when the battery is getting low. Changing the battery is easy too, thanks to a simple compartment.


1. Current Measurement

Here's where these multimeters start to differ:

  • Klein MM300: It can measure up to 10A DC current, which is enough for many tasks. However, it can't measure AC current.
  • Klein MM400: This one is more versatile. It can measure both 10A AC and DC current. So, if you work with different types of current, this is a better choice.

2. Resistance Measurement

Another big difference is how they measure resistance:

  • Klein MM300: It can measure resistance up to 2 million ohms (2MOhms). That's fine for most things you'll do in homes and small businesses.
  • Klein MM400: This one can measure resistance up to 40 million ohms (40 MOhms). If you work on things with higher resistance, like certain industrial systems, this is the one you want.

3. Additional Measurements

The MM400 is like the Swiss Army knife of multimeters. It can do more than the MM300:

  • Klein MM300: This model is great for basic stuff like voltage, current, and resistance. It's straightforward but doesn't have extra tricks.
  • Klein MM400: The MM400 can measure temperature, capacitance, frequency, and duty-cycle. It can also test diodes and check continuity. So, if you need to do these things regularly, this multimeter is your best friend.

4. Accessories

What's in the box can also help you decide:

  • Klein MM300 Package Contents: It comes with simple test leads, batteries, and a user manual. That's enough to start using it right away for basic tasks.
  • Klein MM400 Package Contents: This one includes test leads, batteries, and a thermocouple with an adapter. That extra thermometer-like thing is handy if you need to measure temperature, especially if you work with heating and cooling systems.

5. Price

Last but not least, there's the price:

  • Klein MM300: This one costs a bit more ($51) because of its features and accessories. If you need those features, it's a solid investment.
  • Klein MM400:  It's usually more budget-friendly ($46), which is good if you're watching your wallet.

If you want to check more advanced features then check Klein tools MM600.

Klein MM600 Multimeter Review

Many of you are electricians, and you need a Klein mm600 multimeter. You can't afford to make a mistake when it comes to customer service, especially when you’re dealing with electrical complaints. Your job must be done correctly the first time. Klein mm600 multimeter has all the features that an electrician needs in one small package. Its bigger display allows to view all electrical variables easily. It can easily bear a drop test of 2 meter. As a result, from home use to industrial purpose, you can use it anywhere.

Best Klein Tools MM600 Multimeter


  • It comes with a 4000 counts display.
  • A white LCD backlight gives an ease while doing your job at night.
  • You can measure both AC/DC voltages up to 1000V.
  • It has the capacity to measure current up to 10A.
  • Resistance also plays a major role in testing equipment’s. You can measure resistance up to 40Mohms.
  • It comes with both CAT-III and CAT-IV safety ratings.
  • Temperature measurement is also a must in modern day multimeters. The thing which makes it the best Klein multimeter is its ability to measure temperature from -19°C to 538°C.
  • Ghost voltages makes the test results noisy that’s why Klein mm600 is equipped with LoZ to avoid ghost voltages.
  • If we talk about its water-resistant standards then it has IP42 ingress protection.
  • It is equipped with both diode and continuity test.
  • Robust build
  • Easy to use
  • Has true RMS for non-linear loads
  • Low battery Indication
  • Drains battery faster.

What's in the package?

  • Klein MM600 Multimeter
  • Pair of Test leads
  • Thermocouple
  • 2x AAA batteries
  • Carrying Case
  • Strong alligator clips
  • Earth magnetic hanger

Steps to Use the Klein MM300

Using a multimeter may sound complicated, but with a little guidance, it's actually quite easy. The Klein Tools MM300 and MM400 multimeters are designed to make measuring electricity simple. In this guide, we'll walk you through the steps to use these multimeters effectively.

Step 1: Get Your Multimeter Ready

Before you start measuring, make sure your multimeter is good to go. Here's what you need to do:

  • Check the Battery: Make sure your multimeter has a working battery. If the battery is low, a little light will warn you. Changing the battery is easy, and you can do it yourself.
  • Inspect the Wires: Look at the wires with the pointy ends called "test leads." They should be in good shape without any cuts or breaks. If they're damaged, they won't give you accurate measurements.

Step 2: Pick What You Want to Measure

Both the MM300 and MM400 can measure different things like voltage, current, and resistance. To choose what you want to measure, do this:

  • Turn the Knob: On the front of the multimeter, there's a knob you can turn. It has different things you can measure written around it. Turn the knob to what you want to measure, like "V" for voltage.
  • Set the Range: Inside each measurement, there are different ranges. Start with the highest range and change it if you need to. For example, if you're measuring 120V electricity, start with the 600V range and then adjust it down if you need to for a more exact reading.

Step 3: Connect the Test Leads

Connecting the test leads right is super important to get the right measurements. Here's how:

  • Put the Leads In: Each multimeter has a red test lead and a black test lead. Put the red one in the hole that says "VΩmA", and put the black one in the hole that says "COM." The colors match, so you can't mix them up.

Step 4: Take the Measurement

Now that everything's set up, it's time to measure:

  • Use the Probes: Depending on what you're measuring, touch the pointy ends of the probes to what you want to test. For example, if you're measuring voltage, touch the red probe to the plus side and the black probe to the minus side.
  • Read the Display: Look at the multimeter's screen. It'll show you the measurement in numbers (like volts or ohms). Some multimeters have a digital screen, while others have a needle that moves. Digital screens are easier to read, especially if you're new to this.
  • Wait for It to Settle: If the numbers on the screen keep jumping around, wait until they stop moving. That way, you'll get the right measurement.

Step 5: Turn Off the Multimeter

When you're done measuring, don't forget to turn off the multimeter:

  • Put the Knob on "Off": Turn the knob back to the "Off" spot. This not only turns off the multimeter but also makes sure it won't accidentally measure something when you're not using it.

Which Multimeter Is Best: Klein MM300 vs MM400?

The choice between the klein mm300 vs mm400 ultimately depends on your specific needs and preferences. Here are some scenarios to consider:

Choose the Klein MM300 If:

  1. You Prefer Simplicity: The MM300 is perfect if you want a no-frills multimeter for basic voltage, current, and resistance measurements.
  2. Budget is a Concern: It's typically more budget-friendly, making it an excellent choice for those looking for affordability without compromising quality.
  3. You Don't Need Advanced Features: If you don't require additional measurements like temperature or capacitance, the MM300 covers the essentials.

Choose the Klein MM400 If:

  1. You Need Versatility: The MM400 is the go-to choice if you require a wider range of measurements, including temperature, capacitance, and frequency.
  2. You Work with AC Current: It can measure both AC and DC current, making it suitable for a broader range of applications.
  3. Advanced Electrical Testing: If you frequently work with diodes, duty-cycles, and continuity, the MM400's additional features will be invaluable.
  4. Price is Not a Concern: If you're willing to invest in a feature-rich multimeter, the MM400 is worth considering.

Final Words

In the battle of klein mm300 vs mm400, both multimeters have their strengths and can serve you well in various electrical applications. The MM300 excels in simplicity, durability, and affordability, making it an excellent choice for those who prefer straightforward measurements. On the other hand, the MM400 offers an array of advanced features, including temperature measurement, capacitance testing, and more, making it a versatile option for professionals and enthusiasts who require broader functionality.

When making your decision, consider your specific needs, budget, and the types of measurements you frequently perform. Whether you choose the MM300 or MM400, you can trust in Klein Tools' reputation for quality and durability, ensuring that your investment will stand the test of time on the job site or in your workshop.