Review - My Weigh MX300 Digital Scale

Glenn reviews the My Weigh MX300 digital scale.

Many drip coffee and espresso enthusiasts like to home roast and use a digital scale to measure their green beans more precisely.

Some adventurous types will even measure the weight of each shot for either consistency between shots or trying various dosing experiments.

For whatever reason, you just have to have one more gadget in your coffee lab.

Any old kitchen scale will not do. You need precision. Load cells, with compensating electronic circuitry, back lit LCD's, calibration weights, etc.

The MX300 was ordered online and received in about a week’s time. When it says “palm size digital scale” they were not kidding. It is the size of a hand held calculator – and not a large one at that.

The MX300 is rated to measure up to a maximum of 300 grams with 0.1g accuracy

The protective cover can be used as a measuring tray. The front of the scale has membrane-covered buttons to change scale to grams, ounces, troy ounces and pennyweight. There is a back light button, a tare button and an on/off button. The scale will turn itself off after 2 minutes of inactivity in order to conserve power. The unit is powered by three “AAA” batteries. Although the MX300 didn’t have this particular feature, other models offered by My Weigh have AC adapters as optional equipment. Battery life is reported to be about a year.

If you are ordering any digital scale, the tare feature is one you should not do without.
Set your empty container on the scale and a push of the tare button “zeroes” the digital display so that you are measuring only the contents of the container and not the container itself. The manufacturer advises to immediately remove the object that you are weighing right after taking your reading. In other words, weigh the thing and take it off the scale. Doing so with extend the life and performance of the unit.

The LCD display was large enough and easily visible from a variety of different angles. I had no need to turn on the back light even under relatively dim viewing conditions.

How do you know that the scale is accurate?

At the time of purchase, a 100g calibration weight was optional. I am going to say that the calibration weight is really not optional at all – it is essential. Make sure you buy one with the scale.

The MX300 has a calibration circuit which is actuated in a few key presses. If you forget the procedure, it is printed on the inside of the protective cover. The calibration feature only works with a 100g weight so make sure you don’t order another size weight.

In my case, I could calibrate the scale to 100.1g rather than to the desired 100.0g, which means one of two things:

1. The calibration weight needs calibrating; or
2. The scale is within its margin of error.

I suspect the latter however; I got different readings depending where I put the calibration weight on the weighing pad of the scale. It varied by 0.1 g. Compared to some other reviews I have read, this is slightly disappointing performance as the same weight should measure the same at each of the four corners of the weighing platform. Sometimes removing a tared container would result in a difference of 0.2g – other times it would be bang on.

A small gripe is with the original packaging. There was a small plastic tab protruding out of the battery compartment when I first opened the package. The tab is used to prevent the batteries from inadvertently draining during shipping. You are supposed to pull it out before use, however since I knew better, I took off the protective cover to inspect the battery compartment.

This is a big no-no as you may inadvertently mechanically overload the scale by accidentally pressing on the weighing pad. I only read about the potential for damage by reading the dire warnings in the tiny manual afterwards. Read the manual first! Do not overload the scale! Do not ever go over 300g or the earth will stop rotating…

The protective cover was a bit looser than I would have liked, however it did its job of protecting the weighing platform. Make sure you carefully put it back on after you have finished using your scale.


The scale was priced at around $60 CDN and the calibration weight was several dollars extra. All in all, the price was reasonable compared to less accurate scales with shorter warranties. The warranty for the MX300 is 30 years!

For weighing green beans this unit is more than adequate. It is interesting to note that the display is sensitive enough to weigh a single coffee bean and I figure the margin of error is about one bean.

If I were to use this scale exclusively for weighing green beans, I would buy a scale with a larger capacity. A 500g model with 0.1g accuracy would be ideal. I am splitting hairs at this point because most home roasting appliances (depending on model) can only roast about 100g – 250g at a time. If you are ordering green beans in bulk and splitting the lots with friends, it might be worthwhile to invest in a bigger capacity scale.

Some things I would like to see improved are:

1. A warning label or insert in the original package to warn users about overloading the unit.
2. A better fitting protective cover.
3. An easier calibration procedure.
4. Just a tad better accuracy.

We’ll give the MX300 an overall rating of 6.5 out of 10 for build quality, features, accuracy, documentation and ease of use. The scale would have scored higher if it had better accuracy and consistency.

Glenn is a regular contributor to Coffeecrew. Although he likes gadgets he likes to criticize gadgets even more. He says the world needs better gadgets. Coffeecrew is committed to improving the retail consumer buying experience.


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