Volume Calculator: Calculate Cubic Feet, Gallons & Liters for Any Shape (Free Tool)
You are filling a pool. You are pouring concrete. You are shipping a package. You need to know the volume.
Volume is the amount of space inside a three-dimensional object. It is measured in cubic feet, cubic meters, gallons, and liters.
Getting the volume wrong means ordering too much concrete or not enough water for your pool.
Today, I give you a free Volume Calculator.
You select a shape. Enter the dimensions. The calculator shows volume in multiple units.
The calculator handles:
- Box (rectangular prism)
- Cylinder
- Sphere
- Cone
- Cube
Let me explain how to calculate volume for different shapes.
What is Volume? (Simple Explanation)
Volume is the amount of space inside a 3D object. Think of how much water a tank can hold.
Common units:
- Cubic feet (ft³) – US standard for construction
- Cubic meters (m³) – Metric standard
- Gallons (gal) – Liquids (7.48 gallons per cubic foot)
- Liters (L) – Metric for liquids (1,000 L per cubic meter)
- Cubic yards (yd³) – Concrete and soil (27 ft³ per yard)
Basic formulas:
- Box (rectangular prism): Length × Width × Height
- Cube: Side × Side × Side
- Cylinder: π × Radius² × Height
- Sphere: (4/3) × π × Radius³
- Cone: (1/3) × π × Radius² × Height
Why This Volume Calculator Matters
Here is why you need to calculate volume correctly.
Reason 1: Concrete orders
Concrete is sold by the cubic yard. Calculate the volume of your slab or footing.
Reason 2: Pool water
Pools hold thousands of gallons. Calculate volume to know how much water and chemicals to add.
Reason 3: Shipping and freight
Shipping companies charge by dimensional weight (volume). Calculate to estimate costs.
Reason 4: Fish tanks and aquariums
Aquariums are measured in gallons. Calculate volume to know how many fish you can keep.
Reason 5: Fuel tanks
Oil tanks, propane tanks, and fuel tanks have volume ratings. Calculate to check capacity.
Volume Formulas
Box (rectangular prism):
Volume = Length × Width × Height
Cube:
Volume = Side × Side × Side
Cylinder:
Volume = π × Radius² × Height
Sphere:
Volume = (4/3) × π × Radius³
Cone:
Volume = (1/3) × π × Radius² × Height
LIVE Volume Calculator
Select a shape. Enter dimensions. The calculator shows volume instantly.
📦 Volume Calculator
🔲 Shape
📏 Length
📏 Width
📏 Height
📦 Volume Calculator
Calculate cubic feet, gallons, and liters for any shape
🔲 Shape
Box / Rectangular Prism Cube Cylinder Sphere Cone
📏 Length
📏 Width
📏 Height
📏 Radius
📦 VOLUME
0.00 ft³
0.00 m³
0.00 gal
0.00 L
0%
💡 1 cubic foot = 7.48 gallons. 1 cubic meter = 1,000 liters.
📐 For concrete: 1 cubic yard = 27 cubic feet. For pools: 1 gallon = 3.785 liters.
How to Use This Volume Calculator
Follow these 3 simple steps.
Step 1: Select the shape (box, cube, cylinder, sphere, or cone)
Step 2: Enter the dimensions (length, width, height, radius)
Step 3: Read the volume in cubic feet, cubic meters, gallons, and liters
Real Examples: Everyday Volumes
Example 1: Moving box
- Shape: Box
- Dimensions: 2 ft × 1.5 ft × 1.5 ft
- Volume: 2 × 1.5 × 1.5 = 4.5 ft³
Example 2: Water tank
- Shape: Cylinder
- Radius: 2 ft, Height: 5 ft
- Volume: π × 4 × 5 = 62.8 ft³ = 470 gallons
Example 3: Concrete slab
- Shape: Box
- Length: 10 ft, Width: 10 ft, Height: 0.333 ft (4 inches)
- Volume: 10 × 10 × 0.333 = 33.3 ft³ = 1.23 yd³
Example 4: Fish tank
- Shape: Box
- Length: 3 ft, Width: 1.5 ft, Height: 1.5 ft
- Volume: 3 × 1.5 × 1.5 = 6.75 ft³ = 50.5 gallons
Volume by Shape
Box (rectangular prism):
| Dimensions (ft) | Volume (ft³) | Gallons |
|---|---|---|
| 2×2×2 | 8 | 60 |
| 3×2×2 | 12 | 90 |
| 4×2×2 | 16 | 120 |
| 4×4×4 | 64 | 479 |
| 10×10×10 | 1,000 | 7,481 |
Cylinder:
| Radius (ft) | Height (ft) | Volume (ft³) | Gallons |
|---|---|---|---|
| 1 | 4 | 12.6 | 94 |
| 2 | 5 | 62.8 | 470 |
| 3 | 6 | 169.6 | 1,269 |
| 4 | 8 | 402.1 | 3,008 |
| 5 | 10 | 785.4 | 5,877 |
Sphere:
| Radius (ft) | Volume (ft³) | Gallons |
|---|---|---|
| 1 | 4.2 | 31 |
| 2 | 33.5 | 251 |
| 3 | 113.1 | 846 |
| 4 | 268.1 | 2,006 |
| 5 | 523.6 | 3,918 |
Cube:
| Side (ft) | Volume (ft³) | Gallons |
|---|---|---|
| 1 | 1 | 7.5 |
| 2 | 8 | 60 |
| 3 | 27 | 202 |
| 4 | 64 | 479 |
| 5 | 125 | 935 |
Common Volume Conversions
| From | To | Multiply by |
|---|---|---|
| ft³ | gallons | 7.48 |
| gallons | ft³ | 0.1337 |
| ft³ | liters | 28.32 |
| liters | ft³ | 0.0353 |
| ft³ | yd³ | 0.037 |
| yd³ | ft³ | 27 |
| m³ | ft³ | 35.31 |
| ft³ | m³ | 0.0283 |
Material Volume Reference
| Material | 1 ft³ weighs | 1 yd³ weighs |
|---|---|---|
| Water | 62.4 lb | 1,685 lb |
| Concrete | 150 lb | 4,050 lb |
| Soil (dry) | 100 lb | 2,700 lb |
| Sand | 100 lb | 2,700 lb |
| Gravel | 120 lb | 3,240 lb |
| Steel | 490 lb | 13,230 lb |
Pool Volume Guide
| Pool Size (ft) | Shape | Volume (gal) |
|---|---|---|
| 12×24×4 (avg) | Rectangle | 8,600 |
| 16×32×4.5 (avg) | Rectangle | 17,300 |
| 18×36×5 (avg) | Rectangle | 24,300 |
| 20×40×5 (avg) | Rectangle | 30,000 |
| 24 ft diameter × 4 ft | Round | 13,600 |
| 30 ft diameter × 5 ft | Round | 26,500 |
Formula for rectangular pools: Length × Width × Average Depth × 7.48
Formula for round pools: π × Radius² × Average Depth × 7.48
Concrete Volume for Slabs
| Slab Size (ft) | Thickness (in) | Volume (yd³) |
|---|---|---|
| 10×10 | 4 | 1.2 |
| 10×10 | 5 | 1.5 |
| 10×10 | 6 | 1.9 |
| 20×20 | 4 | 4.9 |
| 20×20 | 5 | 6.2 |
| 20×20 | 6 | 7.4 |
| 30×30 | 4 | 11.1 |
| 30×30 | 5 | 13.9 |
| 30×30 | 6 | 16.7 |
Frequently Asked Questions (FAQs)
1. How do I calculate volume of a box?
Length × Width × Height (all in same units).
2. How many gallons are in a cubic foot?
7.48 gallons.
3. How do I calculate volume of a cylinder?
π × radius² × height.
4. How do I calculate volume of a sphere?
(4/3) × π × radius³.
5. How many cubic feet in a cubic yard?
27 cubic feet.
6. How do I convert cubic feet to gallons?
Multiply by 7.48.
7. How do I calculate water volume in a pool?
For rectangle: L × W × Avg Depth × 7.48. For circle: π × R² × Depth × 7.48.
8. How much concrete do I need for a 10×10 slab at 4 inches?
10 × 10 × (4÷12) = 33.3 ft³ ÷ 27 = 1.23 yd³.
9. What is the volume of a 2x4x8 concrete block?
2 × 4 × 8 = 64 cubic inches = 0.037 ft³.
10. How many liters in a cubic meter?
1,000 liters.
Common Mistakes
Mistake #1: Using diameter instead of radius for circles
Radius is half the diameter. Double-check.
Mistake #2: Mixing units
All dimensions must be in the same unit. Convert inches to feet (÷12).
Mistake #3: Forgetting to convert cubic feet to cubic yards
For concrete orders, divide cubic feet by 27.
Mistake #4: Using wrong formula for sphere
Sphere volume is (4/3)πr³, not (4/3)πr².
Mistake #5: Not accounting for irregular shapes
Break complex shapes into simpler ones.
Volume of Irregular Shapes
For irregular objects (like a rock):
- Fill a container with water
- Measure the water volume
- Submerge the object
- Measure the new volume
- Subtract to find object volume
For irregular rooms:
Break into boxes (rectangular prisms). Calculate each. Add together.
Final Thoughts
Volume calculation is essential for construction, shipping, and home projects.
My Volume Calculator gives you:
- Volume for boxes, cubes, cylinders, spheres, and cones
- Cubic feet, cubic meters, gallons, and liters
- Visual meter
Bookmark this page. Use it for concrete orders, pool water, fish tanks, and shipping.
The next time you need to know how much a container holds, you will have the answer.
Disclaimer: This is an educational tool. For critical measurements, verify with actual dimensions.
External Links (Authority Backlinks):
- Wikipedia – Volume{:target=”_blank” rel=”noopener noreferrer”}
- Wikipedia – Cubic foot{:target=”_blank” rel=”noopener noreferrer”}
- Wikipedia – Gallon{:target=”_blank” rel=”noopener noreferrer”}
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