--- title: "Trapezoid cushion size: which width and length to pick" url: "https://cushionguide.com/answers/trapezoid-cushion-size-selection-width-length/" section: "The Cutting Table" author: "Nate Kowalski, The Pattern Engineer of Detroit" author_url: "https://cushionguide.com/masters/nate/" published: "2026-01-20" updated: "2026-01-20" keywords: "how to order trapezoid cushion size, trapezoid cushion size, angled window seat cushion, bay window cushion order, trapezoid cushion measurements" --- # The size menu only asks for width and length. What do I pick for a trapezoid cushion? *Two boxes, four sides. The size menu quotes a price bracket, partner; your notes carry the pattern.* Also asked as: The calculator only asks for two measurements.; How do I enter trapezoid measurements? > **The quick answer:** Pick the size range that covers your trapezoid's longest side and its deepest depth; that choice only sets the price. Then write the exact long side, short side, depth, both angled sides, thickness and fabric code in the personalization or order-notes box, or upload a marked-up photo. The cushion is cut to those numbers, not to the range. ![Knotted black, gray and cream stripe cushion on an oak-topped bay window seat with linen pillows, a mug and an open book](https://cushionguide.com/media/bay-window-cushions/knotted-stripe-bay-window-cushion-oak-ledge-1600.webp "Cut a little shallower than the oak seat board, the cushion leaves a ledge at the front for a mug and a book.") ## Key facts - The price comes from the maximum length and the maximum width (depth) of the shape. - Choose the closest size range that covers the overall size, for example about 85 × 23.8 in (216 × 60.5 cm). - Exact sides go in the personalization or order-notes box at checkout: long side, short side, depth and both angled sides. - A marked-up photo or drawing with every dimension can be uploaded instead. - The cushion is made to the exact measurements, not to the size range selected. - 2, 3, 4 and 5 in thicknesses cost the same for trapezoid cushions. - On request, the workshop works out the price and sends photos of earlier trapezoid cushions. ## Five boxes to fill before checkout 1. **Length:** your longest side, in inches. 2. **Width:** the deepest point, measured straight front to back, not along a slanted side. 3. **Size range:** the closest bracket that covers both, such as about 85 × 23.8 in (216 × 60.5 cm). 4. **Order notes:** long side, short side, depth and both angled sides, plus thickness and fabric code. 5. **Upload:** one marked-up photo or drawing with every edge labeled, if you prefer drawing to typing. ## Why a four-sided shape gets a two-box menu Picture the smallest rectangle your [trapezoid cushion](https://cushionguide.com/cushions/trapezoid-cushions/) fits inside: longest side by deepest depth. That rectangle sets the price bracket. Nothing more. The shape travels in the notes. One angled [bay window seat](https://cushionguide.com/cushions/bay-window-cushions/) ran about 47 in at the back, 14 in deep and 54 in at the front (120, 35 and 137 cm). Bracket: 54 × 14 in. Pattern: all three numbers plus the slants. What does your longest side measure? Start there, then let the [trapezoid cushion calculator](https://cushionguide.com/studio/trapezoid-cushion-calculator/) check that your slants agree. ## What slows a trapezoid order down - ✗ Choosing the range by the short side. - ✗ Measuring depth along an angled side instead of straight across. - ✗ Leaving the notes box empty. A size range is not a shape. > **Tailor's margin:** A trapezoid cushion is priced by the rectangle it fits inside, longest side by deepest depth. The order notes carry the real shape, all four sides. > The size range on a trapezoid cushion order only sets the price; the cushion is cut to the four sides you write in the order notes. > > — Nate ## Buyer questions **A common question:** How do I order a trapezoid window seat cushion when the size calculator only asks for width and length? **The workshop's answer:** Enter the maximum width and length so the price can be calculated, then write the exact sides in the order notes at checkout. The workshop can also work out the price and send photos of earlier trapezoid cushions. **A common question:** Can I order a bay window seat cushion straight from a marked-up photo? **The workshop's answer:** Yes. Select the size range covering the overall size, for example 85 × 23¾ in (216 × 60.5 cm), give the fabric code and thickness in the personalization box, and upload the photo. The 2, 3, 4 and 5 in thicknesses cost the same. **A common question:** The order form takes only one photo. How do I send the rest of my drawings? **The workshop's answer:** Upload one image and write 'drawings sent via message', then send the rest in the chat or merge them into one image. If attachments are blocked, wait for the workshop's first reply. ## Questions buyers ask next ### Will my trapezoid cushion come out at the full size of the range I chose? No. The range is only a price bracket. The cushion is cut to the exact long side, short side, depth and angled sides written in your notes or marked on your uploaded drawing. ### Should I mail a paper template for an angled window seat? No. A hand drawing with every edge measured, or photos plus measurements, is enough. If you already made a full-size template, photograph it with the measurements marked instead. ### Does a thicker trapezoid cushion cost more? Not between the standard options: 2, 3, 4 and 5 in are priced the same for trapezoid cushions. Write the thickness you want in the notes, next to the four sides and the fabric code. ## Related at the atelier - [How do I label the sides on my trapezoid cushion drawing?](https://cushionguide.com/answers/trapezoid-cushion-drawing-label-sides/): Give every edge of the trapezoid a letter and a length: A, B, C and D for the four sides, plus E and F for clipped corners or end pieces, then add the depth and thickness. - [Bay Window Cushion in Caramel Bouclé With Tonal Piping](https://cushionguide.com/readings/tonal-piped-caramel-bay-seat-cushion-golden-sun/): A bay window cushion makes a small bay feel generous when it fills the seat wall to wall, wears tonal piping so the edge doesn't chop up the space, and stays at a moderate thickness: 4 in (10 cm)… - [Bay Window Cushion in Cream Velvet: Music Room Props](https://cushionguide.com/readings/cream-velvet-trapezoid-window-seat-music-room/): A pale velvet bay window cushion needs few props: sheet music, sheer cafe curtains and a walnut piano do the styling here, and muted dusty mauve piping outlines the cream without a hard line. - [Three-Piece Bay Window Cushion in Teal: Reading the Angled Joints](https://cushionguide.com/readings/teal-three-piece-bay-cushion-angled-joints-closeup/): A bay window cushion is usually made in three pieces: a center trapezoid and two angled wings that butt together on each corner of the bay. - [What measurements do you need for a trapezoid bay window cushion?](https://cushionguide.com/answers/trapezoid-cushion-measurements-needed/): Send every edge of the trapezoid: the front, the back, both angled sides and any clipped corners, plus one straight depth and the thickness. - [My window seat has lift-up lids. Should the cushion be split?](https://cushionguide.com/answers/storage-bench-lift-up-lid-cushion-sections/): Yes: split a storage bench cushion at the lid lines, so each section lifts with its own lid; three lids get three cushions. - [How to measure a trapezoid cushion so the numbers close](https://cushionguide.com/guides/trapezoid-cushion-measurements/) - [Measuring a 3-sided bay window seat cushion, panel by panel](https://cushionguide.com/guides/bay-window-seat-cushion-3-sided/) *± 1/4 in — Nate* --- Written by Nate Kowalski (https://cushionguide.com/masters/nate/) for CushionGuide (https://cushionguide.com/about/). The site explains made-to-measure cushions and the partner workshop makes them; measurements are in inches first. This Markdown mirrors the page at https://cushionguide.com/answers/trapezoid-cushion-size-selection-width-length/