Sandbox Calculator
Calculate how much sand you need for your child's sandbox based on age and dimensions
Sandbox Shape
Round
Circular sandbox
Formula: π × r² × depth
4-sided (Rectangle/Square)
Rectangular or square sandbox
Formula: length × width × depth
5-sided (Pentagon)
Pentagonal sandbox
Formula: (side² × √(25 + 10√5) / 4) × depth
6-sided (Hexagon)
Hexagonal sandbox
Formula: (3 × √3/2 × side²) × depth
Custom Shape
Enter your own area
Formula: area × depth
Child's Age & Sand Depth
Ideal for creative play
Recommended depth: 12.7 cm
Sandbox Dimensions
Longest side of rectangle
Shorter side of rectangle
Example Calculation
Rectangular Sandbox for Preschooler
Dimensions: 150 cm × 100 cm
Age: 3-5 years old (12.7 cm depth)
Volume: 1.5 × 1.0 × 0.127 = 0.191 m³
Sand needed: 0.191 × 1601.9 = ~306 kg
Sandbags: 14 bags (50 lbs each)
Round Sandbox for Toddler
Radius: 75 cm
Age: 2-3 years old (7.6 cm depth)
Volume: π × 0.75² × 0.076 = ~0.134 m³
Sand needed: ~215 kg or 10 sandbags
Age-Based Depth Guide
Safety Tips
Use only clean, playground-grade sand
Cover sandbox when not in use to prevent animals
Provide shade during hot summer days
Regular cleaning and sand replacement needed
Sand Types
Play Sand
Fine, clean sand specifically for children's play
Washed Sand
Cleaned sand free from dust and debris
Silica Sand
Fine, uniform particles ideal for molding
Understanding Sandbox Calculations
Why Age Matters
The depth of sand in a sandbox should be adjusted based on your child's age and developmental stage. Younger children need shallower sand for safety, while older children can enjoy deeper sand for more complex building and creative play.
Shape Considerations
- •Round: Space-efficient, no sharp corners
- •Rectangle: Most common, fits well against walls
- •Pentagon/Hexagon: Unique shapes, more interesting design
Sand Calculation Formulas
Round Sandbox
Volume = π × radius² × depth
Rectangular Sandbox
Volume = length × width × depth
Sand Weight
Sand density: 1,601.9 kg/m³ (100 lbs/ft³)
Pro Tip: Order 10-15% extra sand to account for settling and future top-ups.