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Source: Roblox Creator Hub · CC BY 4.0 · View source · Code samples: MIT Imported 2026-10-03. Formatting adapted for this site.

UDim2

The UDim2 data type represents a two-dimensional value where each dimension is composed of a relative scale and an absolute offset in logical pixels. It is a combination of two UDim data types representing the X and Y dimensions. The most common usages for UDim2 are setting the Size and Position of GuiObjects.

local guiObject = Instance.new("Frame")
guiObject.Size = UDim2.new(0, 300, 1, 0)  -- 300 logical pixels wide; full height of parent
guiObject.Position = UDim2.new(0, 50, 0, 0)  -- 50 logical pixels from the left
print(guiObject.Size) --> {0, 300}, {1, 0}

Constructors

UDim2.new

Returns a new UDim2 with both dimensions set to zero — equivalent to UDim2.new(0, 0, 0, 0). All four components (X scale, X offset, Y scale, Y offset) default to 0.

UDim2.new

Returns a new UDim2 from four numbers that define both axes. Each pair of arguments defines one dimension: xScale and xOffset for the horizontal (X) axis, then yScale and yOffset for the vertical (Y) axis. Scale is a relative fraction of the parent container's size (typically between 0 and 1), while offset is an absolute logical pixel value added after scaling. All parameters default to 0.

-- 50% width + 20 logical pixels padding, full height
local size = UDim2.new(0.5, 20, 1, 0)

Parameters

UDim2.new

Constructs a UDim2 by composing two UDim values directly. The first argument becomes the horizontal dimension (accessible via .X or .Width) and the second becomes the vertical dimension (accessible via .Y or .Height).

local x = UDim.new(0.5, 10)
local y = UDim.new(1, 0)
local size = UDim2.new(x, y)  -- equivalent to UDim2.new(0.5, 10, 1, 0)

Parameters

UDim2.fromScale

Returns a new UDim2 with the given scalar coordinates and no offsets. Equivalent to:

local xScale, yScale = 0.5, 0.25
print(UDim2.fromScale(xScale, yScale) == UDim2.new(xScale, 0, yScale, 0)) --> true

Parameters

UDim2.fromOffset

Returns a new UDim2 with the given offset coordinates and no scaling. Equivalent to:

local xOffset, yOffset = 100, 50
print(UDim2.fromOffset(xOffset, yOffset) == UDim2.new(0, xOffset, 0, yOffset)) --> true

Parameters

Properties

UDim2.X

The UDim component for the horizontal axis. The returned UDim has a .Scale (relative fraction) and .Offset (absolute logical pixels). This property is equivalent to UDim2.Width.

local pos = UDim2.new(0.5, 10, 1, 0)
print(pos.X.Scale)   -- 0.5
print(pos.X.Offset)  -- 10

UDim2.Y

The UDim component for the vertical axis. The returned UDim has a .Scale (relative fraction) and .Offset (absolute logical pixels). This property is equivalent to UDim2.Height.

local pos = UDim2.new(0.5, 10, 1, 0)
print(pos.Y.Scale)   -- 1
print(pos.Y.Offset)  -- 0

UDim2.Width

A synonym for UDim2.X. Returns the UDim component for the horizontal axis, containing both .Scale and .Offset.

UDim2.Height

A synonym for UDim2.Y. Returns the UDim component for the vertical axis, containing both .Scale and .Offset.

Methods

UDim2:Lerp

Returns a UDim2 interpolated linearly between this UDim2 and the given goal. The alpha value should be a number between 0 and 1.

Parameters

Returns

Operators

UDim2 + UDim2 (addition)

Adds both the scale and offset of each axis independently: the result's X scale is the sum of both X scales, the result's X offset is the sum of both X offsets, and likewise for Y.

local a = UDim2.new(0.5, 10, 0, 20)
local b = UDim2.new(0.25, 5, 1, 0)
local c = a + b  -- UDim2.new(0.75, 15, 1, 20)

UDim2 - UDim2 (subtraction)

Subtracts both the scale and offset of each axis independently: the result's X scale is the first X scale minus the second, the result's X offset is the first X offset minus the second, and likewise for Y.

local a = UDim2.new(1, 100, 1, 50)
local b = UDim2.new(0.5, 30, 0, 10)
local c = a - b  -- UDim2.new(0.5, 70, 1, 40)