Box Volume Calculator (Rectangular Prism)
Calculate rectangular boxes, cargo containers, rooms, and packages. Enter your measurements below to calculate instant, accurate volume in gallons, liters, cubic feet, or cubic meters.
Enter Dimensions
Measure your rectangular prism / box and select units for each measurement
How to Calculate Rectangular Prism / Box Volume
Understand the mathematical formula and measurement method
Where l = length, w = width, and h = height. Total Surface Area is A = 2(lw + lh + wh).
Calculation Steps
- 1Measure the internal or external Length (l), Width (w), and Height (h) using a ruler or tape measure.
- 2Multiply the three dimensions together: Volume = Length × Width × Height.
- 3Select your preferred output unit (gallons, liters, cubic feet, or cubic meters) to see the capacity.
Practical Everyday Uses for Rectangular Prism / Box
Where this 3D calculation is applied in construction, shipping, and daily projects
Parcel Shipping & USPS / FedEx Freight
Calculate dimensional weight (DIM weight) and volume to avoid carrier surcharges.
Rectangular Swimming Pools
Find how many thousands of gallons are needed to fill a backyard swimming pool.
Raised Garden Beds
Calculate how many cubic feet or cubic yards of soil and compost you need to purchase.
Frequently Asked Questions
Common measurement questions for rectangular prism / box volume
How do I calculate the volume of a cardboard box?▼
Measure the length, width, and height in inches. Multiply them together to get cubic inches, then divide by 1,728 to find cubic feet.
What is the difference between a cube and a rectangular prism?▼
A cube has all 6 equal square sides (l = w = h), whereas a rectangular prism can have different lengths, widths, and heights.
How many gallons fit in a 1 cubic foot box?▼
Exactly 7.48052 US liquid gallons fit in 1 cubic foot of space.
Explore Other 3D Volume Calculators
Quick links to other shapes in our mathematical suite