Choose a centre postcode
Enter the postcode that should act as the centre of the radius.
Postcodes & Places
UK Postcode Radius Checker
Check whether a target postcode falls within a chosen straight-line radius of a centre postcode.
Source: Postcodes.io (opens in a new tab)Loading calculator…
HOW IT WORKS
How the UK Postcode Radius Checker works
Enter a target and radius
Add the second full postcode and your radius in miles or kilometres.
Check the result
The tool compares postcode-centre great-circle distance with the radius you entered.
COMMON QUESTIONS
Frequently asked questions
Is the radius based on roads?
No. It is a circular straight-line radius from one postcode centre to another.
Can this prove an address is inside a delivery zone?
It can support a simple postcode-centre rule, but postcode areas have physical size. Use address-level or routing data where precision is contractual or operationally critical.
Can I use kilometres?
Yes. You can choose miles or kilometres.
What data source is used?
Postcodes are resolved through Postcodes.io open postcode data.
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Source information
Calculation rules or data are based on Postcodes.io (opens in a new tab) where applicable. Always check the linked official guidance for unusual or high-stakes circumstances.