How Much Concrete Do I Need for a 10x10 Slab?

Planning a 10x10 concrete slab project? Whether you're building a shed base, patio, or small workshop floor, knowing exactly how much concrete you need is crucial for budgeting and avoiding costly mistakes. A 10x10 slab is one of the most common DIY concrete projects, and with the right calculations, you can tackle it confidently.

Quick Answer: For a standard 4-inch thick 10x10 slab, you need approximately 1.23 cubic yards (or 1.35 cubic yards with 10% waste factor). That's about 56 bags of 80lb concrete mix, though ready-mix delivery is more cost-effective and convenient for this size project.

Understanding the Basic Calculation

Calculating concrete volume is straightforward once you understand the formula. Concrete is measured in cubic yards (yd³) in the United States, and the calculation requires three measurements: length, width, and thickness.

The Formula

Here's the step-by-step calculation for a 10x10 slab:

1. Convert thickness to feet: 4 inches ÷ 12 = 0.333 feet
2. Calculate cubic feet: 10 ft × 10 ft × 0.333 ft = 33.3 cubic feet
3. Convert to cubic yards: 33.3 ÷ 27 = 1.23 cubic yards
4. Add waste factor: 1.23 × 1.10 = 1.35 cubic yards (recommended order amount)

Why the Waste Factor Matters

Professional contractors always add 5-10% extra concrete to account for:

• Uneven ground: Small dips and variations in your base
• Spillage: Inevitable waste during pouring and finishing
• Form irregularities: Slight bowing or gaps in formwork
• Over-excavation: Areas dug slightly deeper than planned

Running short on concrete mid-pour is a nightmare scenario. The extra 10% is cheap insurance that ensures you complete your project in one continuous pour, which is critical for slab integrity.

Concrete Amount by Thickness

The thickness of your slab dramatically affects how much concrete you need. Here's a breakdown for a 10x10 slab at different thicknesses:

Choosing the Right Thickness

Your slab thickness depends on its intended use:

• 3 inches: Light-duty walkways only (not recommended for slabs)
• 4 inches: Sheds, patios, light storage (most common for 10x10 projects)
• 5 inches: Workshops, heavier equipment storage
• 6 inches: Vehicle traffic, heavy machinery, driveways

Bagged Concrete vs. Ready-Mix: Which is Better?

For a 10x10 slab, you're at the crossover point where both options are viable. Let's break down the pros and cons:

Bagged Concrete (80lb bags)

Pros:

• No delivery fees or minimum orders
• Can work at your own pace
• Easy to store extras for future repairs
• Good for remote locations without truck access

Cons:

• Requires mixing 56+ bags (exhausting work)
• Inconsistent mix quality between batches
• Takes much longer to complete
• Higher total cost for larger slabs
• Physical strain of mixing and pouring

Cost: 56 bags × $5 = $280 (plus mixer rental ~$75/day) = $355 total

Ready-Mix Concrete (Truck Delivery)

Pros:

• Professional-grade consistent mix
• Pour completed in 30-60 minutes
• Less physical labor required
• Better quality control
• Continuous pour (no cold joints)

Cons:

• Minimum order requirements (usually 1 yard)
• Delivery fees apply
• Must be ready when truck arrives
• Requires truck access to site

Cost: 1.5 yards × $125/yard + $75 delivery = $263 total

Verdict: For a 10x10 slab, ready-mix is actually cheaper and far more convenient. The only reason to use bagged concrete is if you lack truck access or want to work over multiple days.

Step-by-Step: Ordering and Pouring Your 10x10 Slab

1. Prepare Your Site

• Excavate: Dig 6-8 inches deep (4" concrete + 4" gravel base)
• Compact: Compact the soil thoroughly
• Add 4 inches of crushed gravel base
• Compact gravel with a plate compactor
• Build forms using 2×4 or 2×6 lumber
• Ensure forms are level and square

2. Add Reinforcement

For a 10x10 slab, reinforcement is highly recommended:

• Wire mesh: 6×6 W1.4×W1.4 welded wire mesh (one 5'×10' sheet, overlapped)
• Or rebar: #3 rebar in 18-inch grid pattern (about 12 pieces, 10 feet long)
• Use rebar chairs to keep reinforcement centered in slab thickness

3. Order Your Concrete

When calling the ready-mix company, specify:

• Amount: 1.5 cubic yards (includes waste factor)
• Mix strength: 3,000 PSI minimum (3,500-4,000 PSI for heavy use)
• Slump: 4-5 inches (good workability)
• Air entrainment: 5-7% if in freeze-thaw climate
• Delivery time: When you're 100% ready (forms built, reinforcement in place)

4. Pour and Finish

• Have at least 2-3 helpers ready
• Start pouring from the farthest corner
• Spread concrete evenly with a rake
• Screed the surface level with forms
• Float the surface smooth
• Edge around the perimeter
• Add broom finish for traction (or smooth trowel for indoor slabs)

5. Cure Properly

• Keep concrete moist for 7 days minimum
• Cover with plastic sheeting or apply curing compound
• Avoid walking on slab for 24-48 hours
• Wait 7 days before removing forms
• Full strength achieved at 28 days

Common Mistakes to Avoid

1. Underestimating Concrete Needed

Running out mid-pour creates a "cold joint" that weakens your slab. Always order 10% extra. The cost of leftover concrete is far less than the problems caused by running short.

2. Skipping the Gravel Base

Pouring directly on soil invites settling, cracking, and moisture problems. A proper 4-inch compacted gravel base is essential for long-term durability.

3. Inadequate Reinforcement

While you might get away without reinforcement on a small slab, wire mesh or rebar adds minimal cost and dramatically improves crack resistance. It's cheap insurance.

4. Poor Curing

Concrete gains strength through hydration, not drying. Letting it dry too quickly results in weak, dusty concrete that will fail prematurely. Keep it moist for at least 7 days.

5. Ignoring Weather

Don't pour in temperatures below 40°F or above 90°F. Cold weather slows curing; hot weather causes rapid moisture loss and cracking. Ideal temperature is 50-80°F.

Cost Breakdown for a 10x10 Slab

Here's what you can expect to pay for a complete 10x10 concrete slab project:

DIY Cost (Ready-Mix)

• Concrete (1.5 yd³): $188-$263
• Gravel base (0.5 ton): $25-$40
• Wire mesh or rebar: $30-$50
• Lumber for forms: $40-$60
• Misc supplies: $30-$50
• Tool rental (if needed): $50-$100

Total DIY Cost: $363-$563

Professional Installation

• Materials: $363-$563
• Labor: $250-$400

Total Professional Cost: $613-$963

Professional installation typically costs $6-$10 per square foot for a basic slab. For a 10x10 (100 sq ft) slab, that's $600-$1,000 total.

Tools and Materials Checklist

Before starting your project, gather these essentials:

Tools

• Shovel and wheelbarrow
• Plate compactor (rental)
• Level (4-foot minimum)
• Tape measure
• Concrete rake
• Screed board (straight 2×4, 12 feet long)
• Bull float or hand float
• Edging tool
• Broom (for texture)
• Rubber boots and gloves

Materials

• 1.5 cubic yards ready-mix concrete (3,000+ PSI)
• 0.5 tons crushed gravel (#57 stone)
• Wire mesh (5'×10' sheet) or #3 rebar
• Rebar chairs or dobies
• 2×4 lumber for forms (40 linear feet)
• Stakes (2×2, 12 inches long)
• Screws or nails
• Form release oil
• Plastic sheeting for curing

When to Call a Professional

While a 10x10 slab is manageable for experienced DIYers, consider hiring a pro if:

• You've never poured concrete before (practice on a smaller project first)
• Your site has significant slope or drainage issues
• You need the slab to support a building or heavy equipment
• Local codes require permits and inspections
• You don't have 2-3 helpers available
• You lack the necessary tools and equipment

Professional installation adds $250-$400 to your project but guarantees proper execution, saves your back, and often includes a warranty.

Final Tips for Success

1. Check local codes: Many areas require permits for slabs over 100 square feet
2. Call 811: Get underground utilities marked before digging
3. Plan for drainage: Slope your slab 1/4" per foot away from buildings
4. Time it right: Start early in the day when temperatures are moderate
5. Have a backup plan: Know what you'll do if weather turns bad
6. Don't rush: Proper preparation is 80% of a successful pour

A 10x10 concrete slab is an excellent DIY project that adds lasting value to your property. With proper planning, accurate calculations, and attention to detail, you can achieve professional results. Use our calculator above to verify your measurements, and don't hesitate to get professional quotes for comparison.

Remember: the difference between a slab that lasts 5 years and one that lasts 50 years comes down to proper base preparation, adequate reinforcement, and patient curing. Take your time, do it right, and you'll have a solid foundation for decades to come.