How rent is worked out
There's no official rent for a property. The right rent is what a tenant will pay on the open market for a home like yours, in your location, at the time you let it. Letting agents work this out by looking at similar homes that have recently let nearby, then adjusting for your property's size, condition and features.
The averages this checker shows come from the Office for National Statistics Price Index of Private Rents, which tracks the rents tenants actually pay across each council area. They're a reliable starting point, but they cover every type of property in a whole council area, so your own figure could be higher or lower.