Volume Calculator Compute volumes of shapes, tanks, and containers — with 2025 benchmarks, unit conversion, and real-worl...

Volume Calculator

Compute volumes of shapes, tanks, and containers — with 2025 benchmarks, unit conversion, and real-world adjustments.

Standard Shapes

Containers

Irregular Objects

Unit Converter

Shape Cube Sphere Cylinder Cone Pyramid Rectangular Prism

Side / Radius (units)

Height (units)

Unit Meters Centimeters Feet Inches

Output Unit Cubic Meters (m³) Liters (L) US Gallons Cubic Feet (ft³)

Tank Type Vertical Cylinder Spherical Rectangular

Diameter / Width (ft)

Length / Height (ft)

Method Average Dimensions Water Displacement

L × W × H (cm)

Displaced Water (mL)

Value

From m³ Liters US Gal ft³

To US Gal Liters m³ ft³

0.000

Volume

0.000 L

In Liters

0.000 gal

In US Gallons

0.000 ft³

In Cubic Feet

Shape Diagram

Volume Formulas

Cube**:

$$ V = s^3 $$

Sphere**:

$$ V = \frac{4}{3} \pi r^3 $$

Cylinder**:

$$ V = \pi r^2 h $$

Cone**:

$$ V = \frac{1}{3} \pi r^2 h $$

Rectangular Prism**:

$$ V = l \times w \times h $$

Example** (Cylinder, r=5 cm, h=10 cm): $$ V = \pi \times 5^2 \times 10 = \mathbf{785.4\ cm^3 = 0.785\ L} $$

✅ Pro Tip**: For horizontal cylindrical tanks, use segment area × length for partial fills.

Volume Red Flags

⚠️ Avoid these costly errors:

• Unit mix-ups** — entering radius in *inches* but height in *feet* (×144 error!)
• Ignoring wall thickness** — 5mm steel tank wall = 3–5% capacity loss
• 100% fill assumption** — tanks should only be filled to 90–95% for thermal expansion
• Using diameter for radius** — $V = \pi d^2 h$ instead of $\pi (d/2)^2 h$ = 4× overestimate

✅ Pro Tips**:

• Always convert to **one unit system** before calculating
• For irregular objects: – Average dims: (L₁+L₂)/2 × (W₁+W₂)/2 × (H₁+H₂)/2 – Water displacement: 1 mL = 1 cm³
• Use composite volume for complex shapes (e.g., silo = cylinder + cone)

2025 Volume Benchmarks

Object	Dimensions	Volume
Olympic Pool	50m × 25m × 2m	2,500 m³ (660,000 gal)
Oil Drum	22.5″ × 33.5″	0.208 m³ (55 gal)
Fuel Tank (Sedan)	—	50 L (13.2 gal)
80-lb Concrete Bag	—	0.6 ft³ (17 L)

📉 Unit Conversions**:

• 1 m³ = 1,000 L = 264.172 US gal = 35.315 ft³
• 1 ft³ = 1,728 in³ = 7.48052 US gal
• 1 US gal = 3.78541 L

How to Use This Calculator

➡️ Standard Shapes

“Sphere radius 7 cm — volume?” → **1,436.8 cm³** or **1.437 L**

➡️ Containers

“8-ft diameter × 10-ft tall water tank” → **3,769 ft³ = 28,200 gal**

➡️ Irregular Objects

“Box approx. 20×15×10 cm” → **3,000 cm³ = 3 L**

➡️ Unit Converter

“1.5 m³ to US gallons?” → **396.3 gal**

Note: Uses exact π = 3.141592653589793. For tanks, assumes vertical orientation unless specified.