48 well plate dimensions
One footprint, a 13.08 mm grid, and well sizes that split by kind: the numbers that decide whether a plate fits your reader, shaker, and handler.
Every 48 well plate shares the ANSI/SLAS footprint, 127.76 by 85.48 mm, and the 13.08 mm well grid. What varies is well diameter and shape, plate height, and skirt design, and those are the dimensions that decide instrument fit.
The grid and the footprint
Wells sit on a 13.08 mm pitch in 6 rows by 8 columns. The A1 well center sits in the plate's corner region defined by the ANSI/SLAS standards, offset from the two edges so that handlers and readers can address every well from one registration. Because the pitch is exactly two thirds of the 24 well pitch and the grid interlocks with the 96 well grid (every 48 well position coincides with a 96 well position at double spacing), multichannel pipettes set to the right spacing and handler plate definitions treat the format as a coarse 96.
Well sizes by kind
Culture wells are round, about 11 mm across and about 17 mm deep, giving the 1.6 mL brim volume and 0.95 cm2 growth area. Deep well plates replace the round well with square wells of about 16 mm across the top or rectangle wells, reaching 4.8 to 7.5 mL. The well's top opening, not the footprint, is what a cap mat seals against, which is why seals are sold per well pattern.
Heights
A 48 well culture plate stands about 17 to 20 mm tall with its lid. Deep well 48 plates stand several times taller, and the sealed height under a cap mat is the number stackers and shaker clamps care about. Catalogs quote height inconsistently (with lid, without, to the skirt), so measure the physical plate against the instrument's clearance when a fit is close.
The fit checks that matter
- Reader: footprint and skirt, plus height for top-reading instruments with limited travel.
- Shaker: clamp reach against plate height, and whether the plate's base sits flat in the carrier.
- Handler: the plate definition in the software (well count, pitch, height, well depth) and a gripper that matches the skirt.
- Stacker and hotels: sealed height, mat included.
Related guides
Common questions
What is the well spacing of a 48 well plate?
13.08 mm center to center, in both directions, on a 6 by 8 grid. It is the ANSI/SLAS defined pitch for the format and matches the spacing settings on adjustable multichannel pipettes.
Is a 48 well plate the same size as a 96 well plate?
Outside, yes: both are 127.76 by 85.48 mm. Inside, no: the 48 has half the wells at 13.08 mm pitch instead of 9 mm, with wells roughly three times the growth area.
How deep is a 48 well?
A culture well is about 17 mm deep with a 1.6 mL brim volume. Deep well 48 plates run much deeper, sized to their 4.8 to 7.5 mL volumes. Well depth, not plate height, is the number liquid handler aspirate and dispense heights are programmed from.
Where is the A1 well on a 48 well plate?
In the corner the standards define, offset from the top and left edges of the footprint so instruments register consistently. Plates mark A1 with the row and column labels molded along the edges; the top left well when the labels read upright is A1.