18" x 20" Patio Cushions – Custom Made to Your Exact Size

Thickness & Foam for a 18 x 20

An 18 x 20 patio pad is dining-chair geometry: 20 inches of depth gives the thigh room a lounge chair does not, and the thickness question is whether your table still clears knees afterward. Three inches is the spec most frames were built around; 3.5 buys plushness without lifting the sitter out of conversation height; 4 belongs to low frames and slow dinners. If the original pad’s thickness is known, match it — the table height was designed for it.

Density follows duty. A dining set used every evening wants 50D; a weekend balcony set can honestly run 35D; the 60–65D grades are real but rarely earn their cost at dining scale. All four grades cut to this footprint, and the grade is confirmed in writing with your dimensions before production.

This rectangle’s commonest order is a single seat — not a set. The bistro pair on a small balcony where one pad died. The lone patio armchair that came with the apartment. The replacement for a set of four where three pads survived and the fourth did not, and the owner would rather match one pad than replace four good ones. Single-piece orders are the honest use case at this size, and the no-minimums policy is what makes them ordinary: one pad, cut to one seat’s numbers, priced on its own area.

The one-patience note on singles: a new pad sits prouder than its settled neighbors — full loft versus compressed years — and fabric ordered later will not match the first dye lot. If the pad you are replacing had siblings ordered together, replacing in symmetry pairs (or as a set) buys matching; if it genuinely travels alone, none of that matters and the single is the right order.

18 x 20 or 20 x 18?

Dimension order is a convention, and the convention here is width first, depth second — but search boxes and furniture tags do not always honor it. The practical decode: the smaller number is almost always the width (side to side, between the arms), the larger the depth (front to back, the direction your thigh runs). A pad listed 18 × 20 and one listed 20 × 18 are usually the same rectangle — but only usually, because dining-chair decks sometimes run wider than deep.

The check that settles it in ten seconds: sit in the chair. The dimension running the same direction as your thigh is the depth; the one crossing the seat between the arms is the width. Enter them in either order on the form — the confirmation before cutting lists both numbers against both axes, and a swap caught there costs nothing.