A standard full size bed (also called a double) is about 54 inches wide by 75 inches long, which is roughly 4.5 feet by 6.25 feet.

Quick Scoop

Short answer

  • Length: about 75 inches (around 190–191 cm).
  • Width: about 54 inches (around 137 cm).

Some brands list full length as 74–75 inches, but 54" x 75" is the commonly accepted standard.

Mini breakdown

  • Also known as: full or double bed.
  • Compared to a twin: same length (75") but about 15–16 inches wider.
  • Compared to a queen: about 6 inches narrower and 5 inches shorter.

So if you’re asking “how long is a full size bed,” think of it as roughly six and a quarter feet from head to toe.🧵

Common variations you might see

  • Full: 54" x 75" (standard).
  • Full XL: 54" x 80" (same width, 5" longer for taller sleepers).

Sometimes brands tweak the length by an inch (e.g., 74" vs 75"), so it’s smart to double‑check the exact dimensions when buying mattresses, frames, or bedding.

Simple size table (US mattresses)

[10][5][9] [5][9][10] [9][10][5] [10][5][9] [5][9][10] [9][10][5]
Mattress size Dimensions (inches)
Twin 38 x 75
Twin XL 38 x 80
Full 54 x 75 (sometimes 54 x 74)
Queen 60 x 80
King 76 x 80
California King 72 x 84

Information gathered from public forums or data available on the internet and portrayed here.