🕳️ Hole Volume Calculator
Calculate volume of round or square holes
How to Use This Calculator
Enter Hole Dimensions
Input the hole diameter (for round holes) or width (for square holes) and depth in inches. Measure the inside dimensions of the hole for accurate calculations.
Select Hole Shape
Select whether the hole is round (circular), square, or rectangular. Round holes use cylinder volume formula; square/rectangular holes use rectangular prism formula.
Calculate and Review
Click "Calculate Hole Volume" to see hole volume in cubic feet, cubic yards, gallons, and liters. Use this volume to calculate concrete, fill material, or excavation needs.
Apply to Project
Use the calculated volume to order concrete, fill material, or estimate excavation costs. For multiple identical holes, multiply the single hole volume by the number of holes.
Formula
Round Hole: Volume = π × (Diameter/2)² × Depth
Square Hole: Volume = Width² × Depth
Convert Inches to Feet: Divide by 12
Volume (cu yd) = Volume (cu ft) ÷ 27
Volume (gallons) = Volume (cu ft) × 7.48
Example 1: Round Post Hole (12" diameter, 24" depth)
Step 1: Convert to feet: Diameter = 12" = 1 ft, Radius = 0.5 ft, Depth = 24" = 2 ft
Step 2: Calculate volume: π × 0.5² × 2 = 1.57 cu ft
Step 3: Convert to cubic yards: 1.57 ÷ 27 = 0.058 cu yd
Step 4: Convert to gallons: 1.57 × 7.48 = 11.7 gallons
Example 2: Square Hole (12" width, 36" depth)
Step 1: Convert to feet: Width = 12" = 1 ft, Depth = 36" = 3 ft
Step 2: Calculate volume: 1² × 3 = 3 cu ft
Step 3: Convert to cubic yards: 3 ÷ 27 = 0.111 cu yd
Step 4: Convert to gallons: 3 × 7.48 = 22.4 gallons
About Hole Volume Calculator
The Hole Volume Calculator is an essential tool for contractors, excavators, builders, and DIY enthusiasts who need to accurately determine the volume of holes for concrete filling, excavation, or material calculations. This calculator eliminates guesswork by providing precise volume calculations based on hole dimensions and shape, helping you order the right amount of materials without waste or shortages.
When to Use This Calculator
- Post Holes: Calculate hole volume for post foundation concrete filling
- Excavation: Estimate excavation volume for hole digging projects
- Concrete Filling: Determine concrete volume needed to fill holes
- Fill Material: Calculate fill material volume for backfilling holes
- Cost Estimation: Estimate costs for hole excavation or filling materials
Why Use Our Calculator?
- ✅ Accurate Volume Calculation: Precise calculations prevent over-ordering or running short
- ✅ Multiple Shapes: Supports round (circular) and square hole calculations
- ✅ Multiple Units: Shows volume in cubic feet, cubic yards, gallons, and liters
- ✅ Easy to Use: Simple inputs for diameter/width and depth
- ✅ Time Savings: Instant calculations eliminate manual math and measurements
- ✅ Material Planning: Helps order correct amounts of concrete or fill materials
Common Applications
Post Holes: Contractors and homeowners digging post holes use this calculator to determine hole volume for concrete filling. Standard post holes are 12-18 inches in diameter and 24-36 inches deep, which this calculator helps determine accurately.
Excavation: Excavators use this tool to estimate excavation volume for hole digging projects. Accurate volume calculations help estimate excavation costs and material needs.
Concrete Filling: Builders use this calculator to determine concrete volume needed to fill holes. The calculator shows volume in cubic yards for ready-mix concrete ordering.
Tips for Best Results
- Measure Accurately: Use precise measurements for diameter/width and depth for accurate calculations
- Hole Shape: Round holes use cylinder formula; square holes use rectangular prism formula
- For Multiple Holes: Calculate single hole volume, then multiply by number of holes
- Add Waste: Add 5-10% extra for waste, spills, and over-excavation
- Cubic Yards: For ready-mix concrete, order by cubic yards
- Gallons: For liquids or water calculations, use gallons measurement
Frequently Asked Questions
How do I calculate hole volume?
For round holes: Volume = π × (diameter/2)² × depth. For square holes: Volume = width² × depth. Convert all measurements to feet first, then calculate. The calculator does this automatically.
How much concrete do I need to fill a 12-inch post hole?
For a 12-inch diameter, 24-inch deep post hole, you'll need approximately 1.57 cubic feet (0.058 cubic yards) of concrete. This equals about 5-6 bags of 60 lb concrete or 4 bags of 80 lb concrete. Always add 5-10% extra for waste.
What's the difference between round and square holes?
Round holes use cylinder volume formula (π × r² × h), while square holes use rectangular prism formula (width² × height). Round holes are more common for posts and columns; square holes are used for specific applications.
How many gallons of water can a hole hold?
Multiply cubic feet by 7.48 to get gallons. For example, a hole with 1.57 cubic feet volume holds 1.57 × 7.48 = 11.7 gallons. The calculator shows volume in gallons automatically.
Do I need to add extra volume for waste?
Yes! Always add 5-10% extra for waste, spills, and over-excavation. If you need 0.058 cubic yards, order about 0.064 cubic yards (with 10% waste) to ensure you have enough material.
Can I calculate volume for multiple holes?
Yes! Calculate the volume for one hole using this calculator, then multiply by the number of identical holes. For example, if one hole is 0.058 cu yd and you have 10 holes, you need 0.58 cu yd total.