Envelope Size Calculator — Find the Right Envelope
Enter your card or document dimensions to find the right standard UK envelope size with clearance allowance.
Width measurement
Height measurement
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.