Cinema seat plan builder

Start with the room, not the seat count. The building and fire code decides how long a row can be, how much clearance it needs and where the exits go, so have the drawing checked by your code official or approved inspector before you order seats. In the US most codes are based on the International Building Code; our cinema seating buyer's guide sets out its row-spacing rules and the equivalent guidance for England.

Sightlines. On a stadium or raked floor each row should see over the heads in front. Designers express this as a C-value, the clearance between one viewer's eye line and the eyes in the row ahead; the guide above covers it. If you are converting to recliners, plan the rows again rather than swapping seats: they need deeper rows, often new risers, and AMC reported that its full recliner renovations typically lost 64% of seating capacity.

Aisles. Mark aisle columns and cross-aisles as gaps in the builder. Gaps are skipped when seats are numbered, so seat 5 stays seat 5 whether or not there is an aisle beside it, and a row with no seats takes no letter.

Accessibility. In the US, Table 221.2.1.1 of the 2010 ADA Standards sets the minimum number of wheelchair spaces by seat count: 1 for 4 to 25 seats, 2 for 26 to 50, 4 for 51 to 150, 5 for 151 to 300, 6 for 301 to 500, and 6 plus 1 for each 150 or fraction between 501 and 5,000. Each required space needs a companion seat beside it at shoulder alignment (§221.3, §802.3), the spaces must be part of the seating rather than set apart from it (§221.2.2), and at least 5% of aisle seats need a folding or retractable armrest on the aisle side (§221.4). Spaces must be spread across the room; in rooms of 300 seats or fewer, side-to-side spreading is not required if the wheelchair spaces and companion seats sit in the middle half of the row (§221.2.3.1). Stadium-style US movie theaters have a further rule on where the spaces sit, also covered in the seating guide.

The builder checks the count, the companion seats and the middle-half placement. It counts every seat and wheelchair space towards capacity; how your jurisdiction counts, and everything it cannot see, such as space sizes, floor levels and routes, is for your architect and code official. Outside the US the numbers differ: England's Approved Document M, for example, asks for permanent spaces for 1% of capacity plus removable spaces to make a total of six in rooms of up to 600 seats.

• PNG is a clean drawing of the plan with row letters, seat numbers, a legend and the capacity line. Use it in a refurbishment brief, on a quote request to seating suppliers, or for front-of-house signage. Print sends the same drawing to paper.
• CSV is one line per seat: row, seat and type. Open it in a spreadsheet to count seats by price band, order seat-number plates or check a supplier's quote line by line.
• JSON lists every row and seat with its label, type and grid position, plus the full grid. Box office and ticketing systems usually have their own hall editor, and the people who build the hall in them can work straight from this file; where a system accepts seat-map imports, its fields can be mapped across. You can also reopen the JSON here later to change the plan.

Online, that layout becomes the seat map moviegoers pick from. Filmgrail's cinema ticketing software takes the halls, seats and showtimes from the box office system you already run and turns them into a seat map that works with a thumb on a phone.