How Much Concrete Do I Need for a 10x10 Slab?
Planning a 10x10 concrete slab? This comprehensive guide will help you calculate exactly how much concrete you need, choose the right thickness, and estimate your total project cost.
Quick Answer
For a standard 10x10 slab at 4 inches thick:
- Concrete needed: 1.23 cubic yards
- 80lb bags needed: 55-60 bags
- Estimated cost: $150-$250 for ready-mix concrete
Understanding the Basics
Standard Slab Dimensions
A 10x10 slab is 100 square feet. The amount of concrete you need depends primarily on the thickness:
| Thickness | Cubic Yards | 80lb Bags | Typical Use |
|-----------|-------------|-----------|-------------|
| 4 inches | 1.23 CY | 55 bags | Garden shed, small patio |
| 5 inches | 1.54 CY | 69 bags | Heavy shed, workshop |
| 6 inches | 1.85 CY | 83 bags | Vehicle parking, heavy equipment |
Step-by-Step Calculation
The Formula
Volume (cubic yards) = Length × Width × Thickness ÷ 27
Convert all measurements to feet first:
- Length: 10 feet
- Width: 10 feet
- Thickness: 4 inches = 0.33 feet
Calculation:
10 × 10 × 0.33 = 33 cubic feet
33 ÷ 27 = 1.23 cubic yards
Adding Waste Factor
Always add 5-10% extra for:
- Spillage during pour
- Uneven ground
- Form overflow
- Better safe than sorry
1.23 CY + 10% = 1.35 cubic yards (recommended order amount)
Choosing the Right Thickness
4 Inches
Best for:
- Garden sheds
- Small storage buildings
- Decorative patios
- Light foot traffic
Pros: Most economical
Cons: Not suitable for vehicles
5 Inches
Best for:
- Home workshops
- Medium sheds
- Hot tub pads
- Occasionally driven on
Pros: Good middle ground
Cons: Costs 25% more than 4"
6 Inches
Best for:
- Car parking
- RV pads
- Heavy equipment
- Regular vehicle traffic
Pros: Maximum durability
Cons: 50% more material cost than 4"
Cost Breakdown
Ready-Mix Concrete
For 1.35 cubic yards (4" thick with waste):
- Material: $125-$175
- Delivery: $75-$150
- Total: $200-$325
Pros:
- Professional quality
- Consistent mix
- Fast pour
- Less labor
Bagged Concrete
For 1.35 cubic yards:
- 60 bags × $5-6 = $300-360
- Mixer rental: $75/day
- Total: $375-435
Pros:
- Pour at your pace
- No truck access needed
- Work in stages
Cons:
- More expensive
- Hard physical work
- Time consuming
- Inconsistent quality possible
Recommendation: Use ready-mix for 10x10 slabs. It's cheaper and much easier.
Additional Materials Needed
Base Preparation
- Gravel base: 1.5-2 tons ($50-75)
- Landscape fabric: 100 sq ft ($15-25)
- Compactor rental: $75/day
Reinforcement
- Wire mesh (6×6 10/10): 100 sq ft ($30-40)
- Rebar (#3 or #4): 8-10 pieces ($25-40)
- Rebar chairs: 12-15 pieces ($10-15)
Forms
- 2×4 lumber: 40 linear feet ($30-50)
- Stakes: 20 pieces ($15-20)
- Form release oil: 1 quart ($8-12)
Installation Tips
Site Preparation
- Excavate: Dig 6-8 inches deep
- Level: Use a laser level or string line
- Compact: Tamp soil firmly
- Gravel base: 4 inches of crushed stone
- Compact again: Critical step!
Formwork
- Use straight 2×4s
- Stake every 3-4 feet
- Check level constantly
- Brace corners well
- Apply release oil
Reinforcement
- Wire mesh: Center in slab thickness
- Use rebar chairs to position
- Keep 2-3 inches from edges
- Overlap mesh sections 6 inches
Pouring
- Pour in one go if possible
- Start at far corner
- Work towards exit
- Screed level as you go
- Remove air pockets
Finishing
- Bull float: Initial smoothing
- Edge: Round all corners
- Wait: Let bleed water evaporate
- Trowel: Final smooth finish
- Broom: Add texture for grip
- Cure: Keep moist for 7 days
Common Mistakes to Avoid
❌ Skipping the gravel base - Leads to cracking and settling
❌ Inadequate compaction - Slab will settle unevenly
❌ No reinforcement - Cracks develop quickly
❌ Poor drainage - Water pools, freezing causes damage
❌ Rushing the cure - Weak concrete, surface dusting
❌ Wrong thickness for use - Structural failure or waste
Timeline
- Day 1: Excavation and base prep
- Day 2: Gravel, compact, build forms
- Day 3: Install reinforcement, final check
- Day 4: Pour and finish concrete
- Days 5-11: Cure (keep moist)
- Day 12: Remove forms
- Day 28: Full strength reached
Use Our Calculator
Skip the math! Our Concrete Slab Calculator instantly calculates:
- Exact cubic yards needed
- Number of bags (if going that route)
- Cost estimates for your area
- Compares ready-mix vs bagged pricing
Conclusion
For a 10×10 slab:
- 4" thick: Order 1.35 cubic yards ready-mix ($200-325 total)
- Include: Gravel base, wire mesh, proper forms
- Budget: $400-600 for complete DIY project
- Timeline: Plan for 4-7 days start to finish
Professional installation: $800-1,200 including labor.
Ready to start? Use our free calculator to get your exact measurements and current pricing!