Polytunnel Calculator — Cover Area & Growing Space
Calculate polytunnel cover area and growing space.
How We Calculate This
Floor area = Length x Width. The arch is modelled as a semi-circle, so arch length = pi x (Width / 2).
Total cover needed = Arch length x Tunnel length x 1.1 (10% for edge burial and end panels).
Usable growing space subtracts a 60cm central path from the width.
Frequently Asked Questions
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Last updated: February 2026
All calculations are estimates based on standard gardening guidelines. Results may vary with soil conditions, climate, and plant varieties.