Because the price a gym advertises is not the price you pay, and because the same chain will quietly charge you more one stop down the line.
A London gym advertises a monthly rate. On top of it sits a joining fee, often an admin fee, sometimes an annual maintenance charge. None of them appear next to the headline number and none are the same between operators — so a £24.99 gym with a £20 joining fee costs more in year one than a £26.49 gym with none, and there is no way to see that from the outside.
Branch-to-branch pricing makes it worse. Same brand, same kit, same membership — a different price depending on the postcode. Nobody publishes that comparison, because no operator benefits from it.
Every night we read 20 operators' own websites, pull out every published plan, and compute one number: the all-in monthly cost — twelve months of dues plus joining, admin and annual fees, divided by twelve. Then we re-read every source and check that every figure still literally appears on the operator's own page. If that check fails we do not publish, and yesterday's verified data stays up.
Not for placement, not for a badge, not for burying a joining fee. The ordering being honest is the only reason any of this is worth reading.
Around twenty London operators publish nothing at all. They are listed as unpriced. A plausible guess would be indistinguishable from a fact, which is exactly the problem we are trying to fix.
Promotional rates are shown and labelled, but never used in the comparison — they expire and the comparison should not.
Nobody, yet. It costs almost nothing to run. If it ever earns money it will be from gym operators paying for their own market data, or from clearly-labelled referral links that sit on equipment pages and never on a price ranking. If independence and revenue ever conflict, independence wins — it is not recoverable once lost.
351 gyms · 290 with a published price · last checked 19 August 2026 · Is the data fresh?