About RoamMath
RoamMath is built and run by one person, Michal Latal, to answer a simple question honestly: what will my phone and my bags actually cost me abroad?
Why this site exists
Roaming charges, eSIM prices and airline bag fees change often and are rarely stated in one place. RoamMath puts the answer in one place and shows its working: every figure is read from the network's, eSIM provider's or airline's own official page, date-stamped, and re-checked on a schedule. We currently track UK roaming charges for four networks across 40 destinations, eSIM bundles from three providers, and the baggage fees of 12airlines. If we can't verify a number against an official source, we don't publish it as fact.
The full process is on our methodology page.
Editorial independence
RoamMath is independent: it is not owned by, or operated on behalf of, any mobile network, eSIM provider, airline or booking site. Our comparisons are commission-blind. When we say an option is the cheapest, that is based on the verified numbers alone, never on whether a link pays us.
Some pages may contain affiliate links (for example to buy an eSIM, hire a car or get travel insurance). They are always labelled “Affiliate link” next to the link itself, and we may earn a commission if you buy through one, at no extra cost to you. Read the affiliate disclosure for the detail.
RoamMath is part of the =Math family of UK cost calculators, alongside ParkMath, which does the same job for airport drop-off and parking charges.
Contact
Spotted a price that has changed, or anything that looks wrong? Tell us; corrections are the whole point.