How we choose and how we score
Every affiliate comparison has a conflict of interest: we make money if you buy. The only way our scores can be of any use to you is if you can check how they come out. Here is the whole method.
Where the data comes from
From each product's public listing on Amazon.co.uk: title, brand, price, average rating, number of reviews, photographs, feature bullets and the full details table. Prices are recorded with the date we checked them, and that date appears on every entry.
When the Amazon listing is incomplete or contradicts itself —which happens more than it should— we look the figure up in the manufacturer's documentation. If we find two different numbers, we publish the manufacturer's and record the discrepancy on the entry itself.
If a figure appears nowhere reliable, it stays empty. You will see «—» in the tables. We never fill a gap with an estimate dressed up as a measurement. If a manufacturer publishes a number that does not hold up, we say so and leave the field empty rather than repeat it.
How we normalise
Every measurement is converted to a single unit —centimetres, kilos, litres— before it is stored. Without that, two products cannot be compared: one publishes inches, another pounds, another millimetres. From the basic measurements we work out the usable surface, the footprint it takes when folded, and the ratio between the two.
The seven scores
Each product gets a score from 0 to 10 on seven criteria. Four are worked out with fixed formulas from the data; three are editorial judgement and are marked as such. The overall score is the average of the seven.
| Criterion | Type | How it is worked out |
|---|---|---|
| Space efficiency | Calculated | It depends on how the piece saves space. If it folds: 70 % the floor it still takes when folded (10 % of the original scores 10; 40 % scores 0) and 30 % how much working surface you get for every cm² stored. If it is a storage piece that does not fold: how many litres it holds for every square metre of floor it takes. |
| Capacity | Calculated | We measure whatever actually limits each piece: usable surface on the ones you work at, litres on the ones you store things in, and kilos supported on seats and exercise machines. |
| Real ratings | Calculated | The Amazon average rescaled from 3-5 to 0-10, multiplied by a confidence factor based on how many reviews back it, which tops out at 500. A 4.6 with 600 reviews is worth more than a 4.6 with 40. |
| Value for money | Calculated | The average of the other criteria divided by the price. It rewards what gives a lot for a little, not what is merely cheap. |
| Build quality | Editorial | Our judgement on materials, thicknesses, load supported and what the reviews say about stability. |
| Ease of use | Editorial | Whether it needs assembling, how much it weighs and how comfortable it is to fold away day after day. |
| Design | Editorial | Finish, and how well it sits visually in a small home. |
The scales are absolute, not relative to the catalogue. That is deliberate: if we normalised against the best and worst of our own selection, everyone's scores would shift every time we added a product, and an 8 today would not mean the same as an 8 next week.
What happens when a figure is missing
If a product has no folded measurement, we cannot work out its space efficiency with the usual formula. In that case we fall back on what we do know —how compact it is open and what it weighs— and mark that axis with an asterisk on the entry. We would rather show a score flagged as approximate than one that is falsely precise.
How we make money
Through Amazon affiliate commission. If you buy through our links we take a percentage; it costs you nothing extra. That does not change the scores: the commission is all but the same across every product in a category, so we have no incentive to push you towards any one of them. What we do have is an incentive for you to trust what you read and come back.
You can read the detail in the affiliate disclosure.