PLOT TOOLS
Polytunnel size calculator: plan your footprint (UK)
Turn bed dimensions, path width and door position into a layout footprint.
Start with the beds, then add access
Enter the number of beds and the length and width of each one. This layout assumes identical rectangular beds placed side by side. It adds a path between each pair; a single bed gets one path alongside it.
Choose an end door if you want the layout to stop at the ends of the beds. Choose a side door to add one cross aisle, using the same width as the other paths. The calculator does not position the door or check whether it opens into a bed.
The result is a rectangular floor-layout estimate. It does not recommend a standard tunnel size or allow for frame clearance, sloping sides, door clearance or headroom.
A worked layout
Two beds, each 4 m long and 1 m wide, with a 0.6 m path between them need a rectangle 2.6 m wide by 4 m long. That is 10.4 m²: 8 m² of beds and 2.4 m² of path.
Those dimensions are an example, not a recommendation for bed or path width. Change the inputs to suit the layout you want to explore.
How the footprint is calculated
Width = total bed widths + path width × the greater of one or (bed count − one).
Length = bed length, plus one path width when a side door is selected.
Area = layout width × layout length.
The drawing shows the beds, paths and any cross aisle in the layout's relative proportions, with dimension labels. It is not a fixed-scale plan or a drawing of a commercial frame. Do not measure the screen or printout; use the labelled dimensions.
Take the result to the maker
Ask for the usable internal floor plan and door dimensions of the model you are considering. Compare those with your proposed beds and access routes. The calculated footprint alone cannot tell you whether that frame gives enough usable room.
Nearest standard-size matches and a headroom allowance remain unavailable until official dimensions and their assumptions have been checked. No maker specifications are used in this calculation.
Save or print the plan
After calculating, you can explicitly choose Download SVG plan or Print this plan. The download asks your browser to save a plan file; printing opens the browser's print flow. These actions are user initiated. The calculator does not automatically store its inputs or result, and the drawing's printed size is not a physical scale.
Compare a saved layout
After calculating a layout, choose Keep this layout to hold one snapshot on this page. Change the inputs and calculate another layout to see the Current minus saved table for width, length, total area and bed area. A negative difference means the current measure is smaller; a positive one means it is larger. Editing inputs leaves the saved snapshot unchanged. Choosing Keep this layout again replaces it; Clear saved layout or reloading the page clears it. Nothing is saved between visits.
Download SVG plan creates a drawing of the current layout only; it does not include the saved comparison. For a worked example and guidance on reading the differences, see compare polytunnel bed layouts.