Envelope Size Calculator — Find the Right Envelope
Enter your card or document dimensions to find the right standard UK envelope size with clearance allowance.
Space between card edge and envelope (typically 3 mm)
How We Calculate This
This calculator adds a clearance allowance to your card dimensions, then checks which standard UK envelope sizes will fit.
The minimum envelope size is calculated as: card dimension + (clearance x 2) for both width and height.
The calculator checks both orientations (portrait and landscape) against standard C-series, DL and popular square envelope sizes used in the UK.
Frequently Asked Questions
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Last updated: 2025-02-20
All calculations are estimates. Always verify quantities before purchasing materials.