Concrete Calculator for Volume and Cost
Concrete Calculator
Calculate volume and weight of concrete for slabs, columns, tubes, curbs, and stairs. Get accurate estimates for your construction projects.
Concrete Volume Calculator
Enter dimensions for different concrete structures
Slabs, Square Footings, or Walls
Slabs, Square Footings, or Walls - Results
Total Volume
23.18 cubic feet
or 0.86 cubic yards
or 0.66 cubic meters
Total Weight Needed
3081.6 lbs
or 1397.8 kg
Using pre-mixed concrete with density of 2130 kg/m³ or 133 lbs/ft³*
Bag Requirements
Using 60-lb bags: 51.36 bags
Using 80-lb bags: 38.52 bags
Estimated Cost
$65.63
Concrete Settings
Complete Guide to Concrete Calculation & Construction
Professional insights into concrete properties, mixing, curing, and construction best practices
Understanding Concrete Composition & Properties
Concrete is a composite construction material composed of coarse aggregates (sand, gravel, crushed stone, slag) bonded together with cement paste. Portland cement, the most common binding agent, reacts with water in a process called hydration, creating calcium silicate hydrate (C-S-H) gel that hardens and gains strength over time.
Key Components
- • Cement (10-15%): Portland cement, binding agent
- • Water (15-20%): Activates cement hydration
- • Fine Aggregate (25-30%): Sand particles < 4.75mm
- • Coarse Aggregate (35-40%): Gravel, crushed stone > 4.75mm
- • Air (5-8%): Entrapped and entrained air voids
- • Admixtures (0-10%): Chemical additives for specific properties
Concrete Strength Classes
- • C20/25 (20 MPa): Lightweight, non-structural applications
- • C25/30 (25 MPa): Standard residential foundations, slabs
- • C30/37 (30 MPa): Commercial buildings, heavy-duty floors
- • C40/50 (40 MPa): High-rise structures, bridges
- • C50+ (50+ MPa): Ultra-high strength, specialized applications
- • Self-compacting: No vibration required, complex forms
Concrete Mix Design & Proportions
Standard Mix Ratios (by volume)
1:2:4 Mix (15 MPa)
1 part cement : 2 parts sand : 4 parts gravel
Use: Non-structural, pathways, light foundations
1:2:3 Mix (20 MPa)
1 part cement : 2 parts sand : 3 parts gravel
Use: Residential foundations, driveways
1:1.5:3 Mix (25 MPa)
1 part cement : 1.5 parts sand : 3 parts gravel
Use: Structural elements, columns, beams
1:1:2 Mix (40+ MPa)
1 part cement : 1 part sand : 2 parts gravel
Use: High-strength applications, prestressed concrete
Water-Cement Ratio Guidelines
W/C Ratio = Weight of Water / Weight of Cement
- • 0.35-0.4: Ultra-high strength, low permeability
- • 0.4-0.45: High strength structural concrete
- • 0.45-0.5: Standard structural applications
- • 0.5-0.6: General construction, moderate exposure
- • 0.6+: Non-structural, interior use only
Admixture Types & Benefits
- • Plasticizers: Improve workability, reduce water content
- • Accelerators: Faster setting, cold weather concreting
- • Retarders: Slower setting, hot weather, long transport
- • Air entraining: Freeze-thaw resistance, durability
- • Waterproofing: Reduced permeability, basement applications
- • Fiber reinforcement: Crack control, impact resistance
Concrete Curing & Strength Development
Curing Timeline & Strength Gain
Initial Set: 2-4 hours
Surface walkable, forms can be handled carefully
Final Set: 4-8 hours
Concrete hardens, but still gaining strength
7 Days: ~65% strength
Forms can be removed, light loading possible
28 Days: ~90% strength
Design strength achieved, full loading capacity
1 Year: ~110% strength
Continued hydration, maximum strength reached
Proper Curing Methods
- • Water curing: Continuous water spray, ponding method
- • Membrane curing: Plastic sheeting, curing compounds
- • Steam curing: Accelerated strength gain, precast
- • Moist curing: Wet burlap, sand, or sawdust covering
- • Internal curing: Pre-wetted lightweight aggregates
Critical Factors for Quality
- • Temperature: 10-30°C optimal, protect from extremes
- • Humidity: Keep surfaces moist, prevent rapid drying
- • Time: Minimum 7 days moist curing essential
- • Wind protection: Prevent surface moisture loss
- • Early age care: First 24 hours most critical
Concrete Purchasing & Construction Guidelines
Ordering Guidelines
- • Calculate exact volume using this calculator
- • Add 5-10% wastage for typical projects
- • Add 10-15% wastage for complex shapes
- • Round up to next 0.5m³ for delivery efficiency
- • Consider access limitations for concrete trucks
- • Schedule delivery based on placement capacity
- • Prepare site access and equipment in advance
Delivery Options
Ready-Mix Concrete
Delivered by truck, 6-12m³ capacity
Best for: Large pours, structural work
Mini-Mix Trucks
Smaller loads, 1-4m³, better access
Best for: Residential, tight spaces
Bagged Concrete
20kg, 25kg, 40kg bags for mixing
Best for: Small repairs, <1m³ jobs
Quality Control
- • Slump test: Check consistency (50-150mm typical)
- • Temperature check: 5-35°C at delivery
- • Visual inspection: No segregation or bleeding
- • Air content test: 4-8% for freeze-thaw areas
- • Cube sampling: Test specimens for strength
- • Delivery time: Use within 90 minutes
- • Weather conditions: Adjust for temperature
Modern Concrete Technology & Applications
Advanced Concrete Types
Self-Compacting Concrete (SCC)
Flows under its own weight, no vibration needed
Applications: Complex forms, dense reinforcement
Ultra High Performance Concrete
Strength >150 MPa, enhanced durability
Applications: Bridges, high-rise, precast elements
Fiber Reinforced Concrete
Steel, glass, or synthetic fibers added
Applications: Industrial floors, shotcrete, repair
Lightweight Concrete
Reduced density, improved insulation
Applications: High-rise construction, insulating fills
Sustainable Concrete Practices
- • Recycled aggregates: Crushed concrete, reduced waste
- • Supplementary materials: Fly ash, slag, silica fume
- • Carbon capture concrete: CO2 injection during mixing
- • Bio-concrete: Self-healing with limestone-producing bacteria
- • Geopolymer concrete: Alternative to Portland cement
- • Permeable concrete: Stormwater management applications
Digital Tools & Monitoring
- • Concrete apps: Real-time strength monitoring
- • Maturity meters: Temperature-time strength prediction
- • 3D printing: Complex geometries, reduced waste
- • BIM integration: Accurate quantity takeoffs
- • IoT sensors: Continuous curing condition monitoring
- • AI optimization: Mix design and quality prediction
Construction Best Practices & Safety
Site Preparation & Placement
- • Subgrade preparation: Proper compaction, drainage
- • Formwork systems: Accurate alignment, adequate support
- • Reinforcement placement: Correct cover, proper spacing
- • Concrete placement: Minimize segregation, control rate
- • Consolidation: Adequate vibration, remove air voids
- • Finishing operations: Timing, surface texture requirements
- • Joint installation: Control, construction, expansion joints
Weather Considerations
Hot Weather (>30°C): Accelerated setting, plastic shrinkage
Cold Weather (<5°C): Delayed strength gain, freeze protection
Rainy conditions: Surface protection, water-cement ratio
Windy conditions: Rapid moisture loss, surface cracking
Safety & Health Considerations
- • Personal protective equipment: Gloves, boots, eye protection
- • Skin protection: Avoid direct contact with wet concrete
- • Dust control: Respiratory protection during cutting/grinding
- • Machinery safety: Proper training for concrete pumps, mixers
- • Fall protection: Elevated concrete placements
- • Chemical hazards: Cement burns, admixture handling
- • Emergency procedures: First aid for cement-related injuries
Common Problems & Solutions
- • Bleeding: Excess water rise - adjust mix design
- • Segregation: Poor cohesion - control placement height
- • Plastic cracking: Rapid moisture loss - fog spray
- • Cold joints: Delayed placement - proper timing
- • Surface defects: Form release agents, proper finishing
- • Strength issues: Water control, adequate curing
Professional Tip: This calculator provides accurate volume estimates for concrete ordering. Always consult with structural engineers for load-bearing applications and follow local building codes and standards. Consider site-specific factors and weather conditions when planning concrete placement operations.