Use this Cubic Feet Calculator to find the volume of a rectangular space, box, container, or object from length, width, and height. Enter the three dimensions, choose the correct units, then calculate cubic feet and related conversions such as cubic meters, cubic yards, cubic inches, liters, US gallons, and UK gallons.

Important Note: This Cubic Feet Calculator estimates rectangular volume from length, width, and height. It converts each dimension into feet, then applies the formula ft³ = length × width × height.

This calculator is best for rectangular or box-like spaces, rooms, containers, appliances, storage units, packaging, and simple material-volume estimates. It does not account for irregular shapes, rounded corners, wall thickness, unusable internal space, sloped sides, settling, compaction, density, or safe fill level.

For construction, shipping, storage, aquarium/tank use, appliance capacity, or material ordering, confirm the measurement method and add any required waste, clearance, safety, or usable-capacity allowance.

Reviewed by: AjaxCalculators Editorial Team
Last updated: April 28, 2026
Method source: Standard rectangular volume formula using length × width × height, plus common volume conversion factors
Editorial standards: AjaxCalculators Editorial Policy

What This Cubic Feet Calculator Calculates

This calculator finds cubic volume from three dimensions: length, width, and height. It is designed for rectangular or box-shaped spaces where volume can be calculated by multiplying the three side measurements.

The calculator can estimate:

• Cubic feet (ft³)
• Cubic meters (m³)
• Cubic yards (yd³)
• Cubic inches (in³)
• Liters (L)
• US gallons
• UK gallons
• Step-by-step volume calculation

The live tool supports dimension units including in, ft, yd, cm, m, ft / in, and m / cm. Mixed units are useful when measurements are written as feet and inches, such as 5 ft 8 in.

What Cubic Feet Means

Cubic feet, written as ft³, is a unit of volume. It describes how much three-dimensional space something occupies.

One cubic foot is the volume of a cube that measures:

1 ft × 1 ft × 1 ft = 1 ft³

Cubic feet are commonly used for room volume, box volume, appliance capacity, moving storage, shipping space, freezer capacity, soil, mulch, gravel, and other practical volume estimates.

How the Cubic Feet Calculator Works

Common Dimension Conversions

The calculator converts length, width, and height into feet before multiplying them.

Length Unit	Equivalent in Feet	Use Note
1 inch	0.0833333 ft	Divide inches by 12
1 foot	1 ft	Base unit for this calculator
1 yard	3 ft	Multiply yards by 3
1 centimeter	0.0328084 ft	Useful for metric-to-imperial conversions
1 meter	3.28084 ft	Useful for room, box, and container measurements

2) Apply the Cubic Feet Formula

After all dimensions are converted to feet, the calculator multiplies length, width, and height.

Cubic feet = length × width × height

Using symbols:

ft³ = L × W × H

In this formula:

• L is length in feet
• W is width in feet
• H is height in feet

3) Convert Cubic Feet to Other Volume Units

Once cubic feet are calculated, the calculator converts the same volume into other units.

For example:

• Cubic meters = ft³ × 0.028316846592
• Cubic yards = ft³ ÷ 27
• Cubic inches = ft³ × 1,728
• Liters = ft³ × 28.316846592

Volume Conversion Factors Used by the Calculator

The calculator uses standard volume conversion relationships to convert cubic feet into other volume units.

Conversion	Factor	Formula
ft³ to m³	1 ft³ = 0.028316846592 m³	m³ = ft³ × 0.028316846592
ft³ to yd³	1 yd³ = 27 ft³	yd³ = ft³ ÷ 27
ft³ to in³	1 ft³ = 1,728 in³	in³ = ft³ × 1,728
ft³ to liters	1 ft³ = 28.316846592 L	L = ft³ × 28.316846592
liters to US gallons	1 US gallon = 3.785411784 L	US gal = L ÷ 3.785411784
liters to UK gallons	1 UK gallon = 4.54609 L	UK gal = L ÷ 4.54609

US gallons and UK gallons are different sizes, so the calculator displays them separately.

Worked Example: Calculate Cubic Feet

Suppose you have a rectangular box with these dimensions:

• Length: 6 ft
• Width: 4 ft
• Height: 3 ft

Step 1: Use the cubic feet formula
Cubic feet = length × width × height

Step 2: Substitute the values
Cubic feet = 6 × 4 × 3

Step 3: Calculate
Cubic feet = 72 ft³

So, the box has a volume of 72 cubic feet.

Worked Example: Convert Cubic Feet to Cubic Yards

Suppose the calculated volume is 81 ft³, and you want to convert it to cubic yards.

Step 1: Use the cubic-yard conversion
Cubic yards = cubic feet ÷ 27

Step 2: Substitute the value
Cubic yards = 81 ÷ 27

Step 3: Calculate
Cubic yards = 3 yd³

So, 81 cubic feet equals 3 cubic yards.

Worked Example: Convert Cubic Feet to Liters and Gallons

Suppose a container has a volume of 10 ft³.

Step 1: Convert cubic feet to liters
Liters = 10 × 28.316846592
Liters = 283.16846592 L

Step 2: Convert liters to US gallons
US gallons = 283.16846592 ÷ 3.785411784
US gallons ≈ 74.805 US gal

Step 3: Convert liters to UK gallons
UK gallons = 283.16846592 ÷ 4.54609
UK gallons ≈ 62.296 UK gal

So, 10 ft³ equals about 283.17 liters, 74.81 US gallons, or 62.30 UK gallons.

Worked Example: Mixed Feet and Inches

Suppose a storage box measures:

• Length: 3 ft 6 in
• Width: 2 ft
• Height: 1 ft 8 in

Step 1: Convert length to feet
6 in ÷ 12 = 0.5 ft
Length = 3 + 0.5 = 3.5 ft

Step 2: Convert height to feet
8 in ÷ 12 = 0.6667 ft
Height = 1 + 0.6667 = 1.6667 ft

Step 3: Apply the volume formula
Cubic feet = 3.5 × 2 × 1.6667

Step 4: Calculate
Cubic feet ≈ 11.67 ft³

So, a box measuring 3 ft 6 in by 2 ft by 1 ft 8 in has a volume of about 11.67 cubic feet.

How to Use This Cubic Feet Calculator

1. Enter the length of the object, room, box, container, or space.
2. Select the length unit, such as ft, in, yd, cm, m, ft / in, or m / cm.
3. Enter the width and select the correct width unit.
4. Enter the height and select the correct height unit.
5. Click Calculate to find the cubic feet result.
6. Review the additional conversions for cubic meters, cubic yards, cubic inches, liters, US gallons, and UK gallons.
7. Use the step-by-step derivation to verify the calculation path.
8. Use Reset to clear the calculator and start again.

How to Interpret the Result

Result	What It Means	Best Used For
Cubic feet	The main rectangular volume result.	Rooms, boxes, containers, appliances, storage, shipping, and material estimates.
Cubic meters	The same volume in metric units.	Metric construction, international shipping, science, and engineering contexts.
Cubic yards	The same volume in cubic yards.	Concrete, soil, mulch, gravel, fill, and bulk material ordering.
Cubic inches	The same volume in smaller imperial units.	Packaging, small containers, technical measurements, and product capacity checks.
Liters	The same geometric volume in liters.	Container capacity comparisons and metric liquid-volume equivalents.
US gallons	The liter conversion expressed as US gallons.	US liquid-capacity comparisons.
UK gallons	The liter conversion expressed as UK gallons.	UK liquid-capacity comparisons.

Liters and gallons are geometric capacity conversions. They do not guarantee safe fill level, usable internal capacity, overflow allowance, pressure rating, or whether a container is suitable for liquids.

Cubic Feet Formula Summary

What You Want to Find	Formula	Use Note
Cubic feet from feet	ft³ = length(ft) × width(ft) × height(ft)	Use when all three dimensions are already in feet.
Cubic feet from inches	ft³ = length(in) × width(in) × height(in) ÷ 1,728	Use when all three dimensions are in inches.
Cubic meters from cubic feet	m³ = ft³ × 0.028316846592	Converts cubic feet to metric volume.
Cubic yards from cubic feet	yd³ = ft³ ÷ 27	Useful for bulk material estimates.
Cubic inches from cubic feet	in³ = ft³ × 1,728	Useful for smaller objects and packaging volume.
Liters from cubic feet	L = ft³ × 28.316846592	Useful for capacity comparisons.
US gallons from liters	US gal = L ÷ 3.785411784	Uses the US gallon definition.
UK gallons from liters	UK gal = L ÷ 4.54609	Uses the UK imperial gallon definition.

Cubic Feet Conversion Table

Cubic Feet	Cubic Meters	Cubic Yards	Liters
1 ft³	0.0283 m³	0.0370 yd³	28.3168 L
5 ft³	0.1416 m³	0.1852 yd³	141.5842 L
10 ft³	0.2832 m³	0.3704 yd³	283.1685 L
25 ft³	0.7079 m³	0.9259 yd³	707.9212 L
50 ft³	1.4158 m³	1.8519 yd³	1,415.8423 L
100 ft³	2.8317 m³	3.7037 yd³	2,831.6847 L

Cubic Feet vs Square Feet

Cubic feet and square feet are different measurements. Square feet measure area, while cubic feet measure volume.

Measurement	What It Measures	Formula	Example Use
Square feet	Area	length × width	Floor area, wall area, land area, surface coverage
Cubic feet	Volume	length × width × height	Room volume, box capacity, container volume, storage space

For example, a floor may be 120 square feet, but the room’s air volume also depends on ceiling height. A 120-square-foot room with a 10-foot ceiling has:

120 × 10 = 1,200 ft³

When to Use a Cubic Feet Calculator

A cubic feet calculator is useful whenever you need volume from length, width, and height.

Common uses include:

• measuring box volume
• estimating room volume
• checking storage-unit capacity
• calculating refrigerator or freezer capacity
• estimating shipping or packaging volume
• estimating aquarium or tank capacity as a geometric volume
• planning soil, mulch, gravel, or concrete volume
• checking appliance, cabinet, drawer, or container space

Important Assumptions and Limitations

Assumption or Limitation	What It Means
Rectangular shape assumption	The calculator assumes the shape is rectangular or box-like.
Uses length × width × height	Volume is calculated by multiplying three perpendicular dimensions.
Measured dimensions required	The result depends on accurate length, width, and height inputs.
No irregular-shape adjustment	Rounded corners, curved sides, sloped sides, cylinders, cones, spheres, and irregular spaces need different formulas.
No wall-thickness correction	Outside measurements may not equal internal usable capacity.
No usable-space guarantee	Internal obstructions, shelves, handles, vents, packaging, or clearance needs may reduce usable volume.
No density or weight conversion	Material weight requires density. Cubic feet alone does not tell you how heavy something is.
Loose materials may settle	Soil, mulch, gravel, sand, and firewood can compact, settle, or contain air gaps.
Liquid capacity is geometric only	Liters and gallons assume full geometric capacity, not safe fill level or overflow allowance.
Rounded results	Displayed values may be rounded for readability.

Common Mistakes to Avoid

Mistake	Why It Causes Problems
Multiplying inches and calling the result cubic feet	Inches × inches × inches gives cubic inches. Divide by 1,728 to convert to cubic feet.
Confusing square feet with cubic feet	Square feet measure area; cubic feet measure volume.
Forgetting height or depth	Volume requires three dimensions, not just length and width.
Mixing units without converting	Feet, inches, yards, centimeters, and meters must be converted consistently.
Using outside dimensions for internal capacity	Wall thickness and internal obstructions can reduce usable volume.
Using cubic feet alone to estimate weight	Weight depends on material density, moisture, compaction, and packing.
Assuming US gallons and UK gallons are the same	US gallons and UK imperial gallons use different definitions.
Using rectangular volume for cylinders or irregular shapes	Round tanks, pipes, barrels, cones, spheres, and irregular spaces require different formulas.

Practical Uses

This Cubic Feet Calculator can be useful for:

• calculating the volume of a box
• measuring moving-box capacity
• checking room air volume
• estimating storage space
• calculating refrigerator or freezer size
• estimating shipping volume
• planning landscaping material volume
• converting cubic feet to cubic meters, liters, or gallons
• checking cubic yards for bulk material orders

When You May Need a Different Calculator

This calculator is best for rectangular volumes. If the object, space, or material problem is not rectangular, use a calculator or formula that matches the shape or material type.

Need	Better Tool or Method
Round tanks, pipes, barrels, or tubes	Use a cylinder volume calculator.
Concrete slabs, footings, or columns	Use a concrete calculator.
Gravel, soil, mulch, or sand coverage with depth	Use a material-specific calculator with density and waste allowance.
Bulk material orders by cubic yard	Use a cubic yard calculator.
Volume from multiple geometric shapes	Use a general volume calculator and add the section volumes.
Convert volume to weight	Use material density: weight = volume × density.
Find floor or wall area only	Use an area or square footage calculator.
Find liquid safe-fill capacity	Use manufacturer capacity data or a liquid-capacity method with safe-fill allowance.

Frequently Asked Questions

How do I calculate cubic feet?

Multiply length, width, and height after converting all three dimensions into feet. The formula is ft³ = length × width × height.

How many cubic feet are in one cubic yard?

There are 27 cubic feet in one cubic yard because 1 yard equals 3 feet, and 3 × 3 × 3 = 27.

How many cubic inches are in one cubic foot?

There are 1,728 cubic inches in one cubic foot because 1 foot equals 12 inches, and 12 × 12 × 12 = 1,728.

Is cubic feet the same as square feet?

No. Square feet measure area, while cubic feet measure volume. Cubic feet require length, width, and height.

Can I use cubic feet to estimate material weight?

Not by itself. To estimate weight, you also need material density. Soil, sand, gravel, mulch, and firewood can vary by moisture, compaction, and packing.

Can I use this calculator for round tanks or pipes?

No. This calculator uses a rectangular volume formula. Round tanks, pipes, barrels, and cylinders need a cylinder volume formula.

Are liters and gallons exact usable capacity?

They are geometric volume conversions. Real usable capacity may be lower because of safe fill level, wall thickness, shape, fittings, or internal obstructions.

Why does the calculator show both US gallons and UK gallons?

US gallons and UK imperial gallons are different sizes, so they should not be used interchangeably.

References

1. NIST Guide to the SI — Appendix B.8: Conversion Factors
2. NIST Guide to the SI — Appendix B.9: Factors by Quantity or Field of Science
3. NIST — Approximate Conversions from U.S. Customary Measures to Metric
4. BIPM — SI Base Units
5. BIPM — The International System of Units SI Brochure

Related Calculators

• Cubic Yard Calculator
• Volume Calculator
• Square Footage Calculator
• Area Calculator
• Gravel Calculator
• Concrete Calculator
• Cord of Wood Calculator
• Length Converter

Cubic Feet Calculator Disclaimer

This Cubic Feet Calculator provides rectangular volume estimates from length, width, and height. It is suitable for box-shaped spaces, rooms, containers, storage, packaging, and simple volume conversions.

It does not account for irregular shapes, rounded corners, curved sides, wall thickness, internal obstructions, unusable space, sloped surfaces, settling, compaction, density, moisture, packing gaps, safe fill level, overflow space, pressure rating, or manufacturer-rated usable capacity.

For construction, shipping, storage, appliance capacity, liquid containers, aquariums, tanks, or material ordering, confirm the measurement method and add any required waste, clearance, safety, or usable-capacity allowance before relying on the result.