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Best practice: How to quickly and accurately calculate BMI

Best practice: How to quickly and accurately calculate BMI


Body Mass Index is the main screening tool to indicate whether a person is - based on their height - underweight, overweight or a healthy weight – and how to calculate it is the latest in our best practice series of blog posts.

Previously we’ve taken a look at ‘how to weigh someone in a bed’, ‘how to use hoist scales’ and ‘how to weigh someone in a wheelchair’.

This post will take you through how and why BMI is used, and then we’ll show you how to use the function which features on all Marsden medical scales fitted with the DP-3810 indicator.



What is BMI?

BMI is probably the most common way of determining overall body health and whether a person is overweight or not.

Because BMI is such a commonly-used measure - simply a person’s weight in kilograms divided by the square of their height in metres - it means national (and international) figures can be compared and the overall body health of a nation can be determined. Alternatively you can calculate it on your Marsden weighing scale by following the instructions below.

If a person’s BMI is out of the healthy BMI range, their health risks may increase significantly.

However, BMI does not provide an indication of the distribution of body fat, and does not adjust for the effects of body shape, therefore it is best to use alongside other body composition readings.

Find out more in this white paper.



How to calculate BMI quickly and accurately

To calculate BMI on any Marsden scale fitted with the DP-3810 indicator, simply follow these instructions.

To switch on the scale press the ON/OFF button. The scale will then start up and display 0.00kg.

Press the BMI button and the bottom display will flash. You can then enter your own or the person you are weighing’s height by using the numeric keypad on the indicator.

Stand on the scale and your weight will be calculated. The BMI reading will be displayed on the bottom of the screen.

For further assistance, watch a video of how to calculate BMI on your scale here.



BMI resources

As the UK is set to be the most obese country in Europe, an understanding of BMI is crucial in preventing the epidemic.

Read more about why measuring BMI is important here.

The Government has recommended that all patients are weighed by default in order to spot concerns of BMI at the earliest opportunity.



Scales with the Marsden DP-3810 indicator

The DP-3810 is Marsden’s premium indicator. It’s the easiest way to calculate BMI, because it has a full numeric keypad, and a display specifically for showing BMI alongside weight and height. Plus, go for the optional automatic height measure available on a number of our DP-3810-equipped scales and the BMI will be automatically calculated and displayed instantly.

The Marsden M-100 is a premium-quality column scale with a large weighing platform and height measure. An optional printer is available to keep a record of the weight reading.

For patients who are unable to stand, the Marsden M-210 can also be used to calculate BMI and means patients can be moved between rooms and weighed using the same device.

The Marsden M-510 is a portable medical scale fitted with the DP-3810 indicator. It’s perfect for GP surgeries, weight management clinics and outpatient departments.


Browse all of our medical scales here. For more information about BMI, contact the team on 01709 364296 or email us here.