Width of a Rectangle Calculator
Calculate the width of a rectangle using area, perimeter, diagonal, or length with step-by-step solutions
Calculate Rectangle Width
The longer side of the rectangle
Total area of the rectangle
⚠️ Please enter a positive length value
Rectangle Width Result
Example Calculations
Example 1: Using Area and Length
Given: Area = 20 m², Length = 4 m
Formula: w = A ÷ h
Calculation: w = 20 ÷ 4 = 5 m
Answer: Width = 5 m
Example 2: Using Perimeter and Length
Given: Perimeter = 18 m, Length = 6 m
Formula: w = (P ÷ 2) - h
Calculation: w = (18 ÷ 2) - 6 = 9 - 6 = 3 m
Answer: Width = 3 m
Example 3: Using Diagonal and Length
Given: Diagonal = 5 m, Length = 4 m
Formula: w = √(d² - h²)
Calculation: w = √(5² - 4²) = √(25 - 16) = √9 = 3 m
Answer: Width = 3 m
Rectangle Properties
Area
A = width × length
Total space inside rectangle
Perimeter
P = 2(width + length)
Distance around rectangle
Diagonal
d = √(width² + length²)
Corner to corner distance
Width Formulas
w = A ÷ h
From area and length
w = (P ÷ 2) - h
From perimeter and length
w = √(d² - h²)
From diagonal and length
Understanding Rectangle Width Calculations
What is Rectangle Width?
The width of a rectangle is one of its two dimensions, conventionally the shorter side. However, when a rectangle is positioned horizontally, the horizontal side is often referred to as the width regardless of its actual length.
Why Calculate Width?
- •Planning construction and architecture projects
- •Calculating material requirements
- •Solving geometry problems
- •Designing layouts and floor plans
Formula Derivations
From Area:
A = w × h → w = A ÷ h
From Perimeter:
P = 2(w + h) → w = (P ÷ 2) - h
From Diagonal:
d² = w² + h² → w = √(d² - h²)
Note: All measurements must be in the same unit for accurate calculations.