Size to Weight Calculator (Rectangular Box) - Calculate Box Weight from Dimensions

Free calculator to determine rectangular box weight based on dimensions and material density for construction, shipping, and DIY projects

Updated: August 2025 • Free Tool

Size to Weight Calculator

in
in
in
lb/ft³

Results

Box Weight
0 lb
Volume 0 cu ft
Volume (cu in) 0 cu in
Surface Area 0 sq ft
Material Density 0 lb/ft³

What is a Size to Weight Calculator?

A Size to Weight Calculator is a free construction tool that helps you calculate the weight of rectangular boxes and containers based on their dimensions and material properties. It determines the volume and weight for shipping, storage, and structural calculations.

For comprehensive construction planning, you might also need our Square Feet to Cubic Yards Calculator for volume conversions, Septic System Calculator for system sizing calculations, or Roof Truss Calculator for lumber and material calculations.

This calculator works for:

  • Shipping calculations - Determine package weight for carriers
  • Storage planning - Calculate load capacities and space requirements
  • Construction materials - Estimate weight of concrete, wood, and metal boxes
  • DIY projects - Plan for material handling and transportation

How Size to Weight Calculator Works

The calculation uses the formula:

Volume = (L × W × H) ÷ 1,728
Weight = Volume × Density

Where:

  • L, W, H = Length, Width, Height in inches
  • Volume = Internal volume in cubic feet
  • Density = Material density in pounds per cubic foot

Key Concepts Explained

Material Density

Weight per unit volume of material. Common values: wood (40-50 lb/ft³), concrete (125 lb/ft³), steel (168 lb/ft³).

Volume Calculation

Converts cubic inches to cubic feet by dividing by 1,728 (12³). Essential for consistent density calculations.

How to Use This Calculator

1

Enter Dimensions

Input length, width, and height in inches

2

Select Material

Choose material type or enter custom density

3

Get Results

View volume, weight, and surface area calculations

Benefits of Using This Calculator

  • •
    Accurate shipping costs - Calculate exact package weights for carrier pricing
  • •
    Structural planning - Determine load capacities and support requirements
  • •
    Material estimation - Plan for transportation and handling equipment

Factors That Affect Your Results

1. Material Type

Different materials have varying densities. Wood ranges from 25-70 lb/ft³, metals are much denser.

2. Wall Thickness

Calculator assumes solid material. For hollow or thick-walled boxes, actual weight may vary.

3. Moisture Content

Wood and some materials absorb moisture, affecting density and weight calculations.

Size to Weight Calculator (Rectangular Box) - Free online calculator to calculate box weight from dimensions and material density for construction, shipping, and DIY projects
Professional size to weight calculator interface for rectangular boxes. Features input fields for dimensions, material selection, and density calculations. Provides instant weight calculations for construction and shipping applications.

Frequently Asked Questions (FAQ)

Q: How do I calculate the weight of a rectangular box?

A: Multiply length × width × height to get volume in cubic inches, divide by 1,728 to convert to cubic feet, then multiply by material density in pounds per cubic foot.

Q: What is the difference between volume and weight?

A: Volume measures space occupied (cubic feet/inches), while weight depends on both volume and material density. Two boxes of same size can have different weights if made of different materials.

Q: Why do I need to know box weight?

A: Weight calculations are crucial for shipping costs, structural integrity, transportation planning, and ensuring compliance with weight limits for various applications.

Q: What materials can I calculate with this tool?

A: The calculator supports wood, plastic, concrete, steel, lead, and custom materials. Each has predefined densities, or you can enter your own density value.