It was with some trepidation that I stripped down to my underwear and stepped into the booth.
The Size-Stream Scanner, as it's known, is currently just a prototype and is merely a space with a curtain pulled around it, fitted with 10 sensors, all trained on different parts of me. The music starts up, I place my feet on the marked spot, and grab a pair of handles.
Within seconds the machine has my precise dimensions after taking three scans of my body. On a screen outside I get to see myself modelled in 3D.
"We get to construct a body model of you, with all the lumps and bumps, so it's very personalised," explains Jim Downing, the chief technical officer of Metail, the Cambridge company that's developing this new tech.
You can say that again.
I look at myself aghast, silently concluding that my slightly fitful New Year diet regime clearly needs stepping up.
The idea is that you can then dress the virtual model of yourself in various outfits online and see how they look from all angles. The retailer can also send you fashion ideas as new designs come in, as modelled by your digital avatar.
"Everybody has the ability to look great," says Metail founder Tom Adeyoola. "There's no reason why we won't move to a future where the idea of size disappears. It's about dressing the best for your shape to make you feel good."
But I'm told the slow take-up of this kind of tech in Western clothing outlets is partly because retailers are concerned that customers - like me - may be put off by what they see.
"If people want the most accurate way of capturing their body shape this is a great way of doing it," says Mr Adeyoola.
"But we want the easiest way, so we also built a statistical model. For a woman, if you enter height, weight and bra size, plus your general shape - hour-glass or pear-shaped - you can get a sense of what your fit will be that's 92% to 96% accurate."
But he reckons that in time both of these methods will be overtaken by the mobile phone, which will become "an exceptionally good and accurate tape measure".
One company with similar ideas is Japanese online fashion retailer Zozo.
It sends customers a figure-hugging body stocking featuring unique positioning spots all over it. You squeeze into the bodysuit, stand in front of your mobile phone and turn 360 degrees while the phone takes snaps of you to create a 3D model of your shape.
You can then order "custom fit" clothes from a currently limited range.
It's an interesting idea, but when my colleagues on our Technology desk tried out the Zozosuit, they found that it didn't work so well.
And this is the big challenge for online fashion retailers. Shoppers love the convenience but they can't try the clothes on first, so returns are high, and this adds a layer of cost which is often passed on to customers.