Concrete Bags vs Ready-Mix: Calculator & Complete Cost Comparison

Standing in the concrete aisle staring at pallets of 80-pound bags, you might wonder: should I load up my truck or call for a concrete mixer? This decision impacts your budget, timeline, and back—often in ways you don't realize until it's too late. The right choice depends on project size, but there's a clear mathematical break-even point where one option becomes obviously better.

Quick Answer: Use bagged concrete for projects under 0.5 cubic yards (small repairs, 4-6 fence posts, tiny slabs). Consider ready-mix for 1+ cubic yards. The break-even is around 0.75-1.0 cubic yards—bagged costs more in materials and massive labor, while ready-mix saves time and physical strain despite delivery fees.

The Math: Cost Per Cubic Yard Comparison

Bagged Concrete Costs

80-lb Bags (Most Common):

• Coverage: 0.6 cubic feet per bag
• Price: $4.50-$6.50 per bag (2025 prices)
• Bags needed per cubic yard: 45 bags
• Cost per cubic yard: $200-$290

60-lb Bags:

• Coverage: 0.45 cubic feet per bag
• Price: $3.50-$5.00 per bag
• Bags needed per cubic yard: 60 bags
• Cost per cubic yard: $210-$300

40-lb Bags (Small Projects):

• Coverage: 0.3 cubic feet per bag
• Price: $2.50-$3.75 per bag
• Bags needed per cubic yard: 90 bags
• Cost per cubic yard: $225-$340

Ready-Mix Concrete Costs

• Concrete price: $125-$145 per cubic yard
• Delivery fee: $75-$150 (one-time, covers 1-10 yards)
• Small load fee: $50-$100 (under 3-4 yards typical minimum)
• Effective cost per yard:
• 1 yard: $250-$395 total ($250-$395/yd)
• 2 yards: $325-$490 total ($163-$245/yd)
• 3 yards: $450-$610 total ($150-$203/yd)
• 5 yards: $700-$875 total ($140-$175/yd)

Break-Even Analysis

Let's calculate exactly where each option makes financial sense:

Key Insight: This analysis assumes you don't value your time or physical effort. When you factor in the hours of mixing and the backbreaking labor, ready-mix becomes attractive at even smaller volumes.

The Hidden Cost: Your Time and Energy

What 45 Bags Actually Means

One cubic yard = 45 eighty-pound bags = 3,600 pounds of material to:

• Load into your vehicle (pray your suspension survives)
• Unload at home
• Carry to mixing area
• Cut open and dump into mixer
• Add water and mix (5-10 minutes per batch)
• Transport mixed concrete to forms
• Pour and finish before it sets

Time investment: 6-10 hours of grueling physical labor

Physical toll: High risk of back strain, exhaustion, and next-day soreness

If your time is worth $20/hour, you're adding $120-$200 in opportunity cost. Suddenly that "cheaper" option isn't cheap at all.

Mixing Equipment

Beyond 10-15 bags, hand mixing in a wheelbarrow becomes impractical. You'll need:

• Electric mixer rental: $50-$75/day
• Gas-powered mixer rental: $75-$100/day
• Wheelbarrow: $60-$120 (if you don't own one)

Add equipment costs and your "savings" shrink further.

When Bagged Concrete Makes Perfect Sense

Ideal Projects for Bags

1. Fence post installation: 2-3 bags per post, work at your pace
2. Small repairs: Crack filling, step repair, minor patches
3. Mailbox posts: 1-2 bags
4. Deck footings: 4-6 posts = 12-20 bags (manageable)
5. Small stepping stones: Work on them over days or weeks
6. Basketball hoop base: 8-12 bags

Advantages of Bagged Concrete

• No scheduling pressure: Mix and pour at your own pace
• No minimum order: Buy exactly what you need
• Easy storage: Keep extra bags for future projects
• No delivery coordination: Work fits your schedule
• Remote locations: No delivery access issues
• Learning curve: Mistakes are less costly with small batches

Best Practices for Bagged Concrete

1. Calculate precisely: Buy 10% extra, but avoid massive over-purchasing
2. Check freshness: Squeeze bags—avoid hard lumps indicating moisture exposure
3. Mix thoroughly: No dry spots, consistent color throughout
4. Correct water ratio: Follow package instructions exactly—too much weakens concrete
5. Work continuously: Don't let mixed concrete sit over 20 minutes
6. Plan logistics: Stage bags near mixing area to minimize carrying

When Ready-Mix is the Clear Winner

Projects That Demand Ready-Mix

1. Driveways: Even small 10×10 sections need 1.2+ yards
2. Garage floors: Typical 20×20 = 5 yards
3. Patios over 100 sq ft: Consistent quality matters
4. Foundation work: Code may require certified ready-mix
5. Any project over 1.5 yards: Economics and practicality favor ready-mix

Advantages of Ready-Mix

• Consistent quality: Computer-controlled batching ensures proper ratios
• Speed: 10 minutes to pour vs. 10 hours of mixing
• Strength certification: Lab-tested mix designs
• No cold joints: Single continuous pour prevents weak seams
• Professional finishing: More time to float and finish properly
• Additives available: Accelerators, retarders, fiber, color

Ready-Mix Ordering Tips

1. Order 10% extra: Short loads are expensive; leftover is cheap insurance
2. Confirm access: Measure clearances—trucks need 12'+ height, 10'+ width
3. Have backup plan: Rent a pump ($400-600) if truck can't reach
4. Schedule strategically: Early morning or late afternoon avoid peak heat
5. Prepare completely: Forms, reinforcement, tools ready before truck arrives
6. Have helpers: 4-5 people minimum for efficient unloading
7. Know wait limits: Trucks charge $2-4/minute after 5-10 minutes

Hybrid Approach: Best of Both Worlds

For certain projects, combining both methods makes strategic sense:

Scenario: 10×12 Patio with Footings

• Footings (4 corners): 12 bags over 2 days (work at your pace)
• Main slab: 1.5 yards ready-mix (single pour, no cold joints)

This approach lets you tackle prep work gradually while ensuring the critical slab gets professional-quality concrete and a continuous pour.

Scenario: DIY Concrete Countertop

• Test batch: 1-2 bags to practice finishing techniques
• Final pour: Calculate exact volume, use bags (countertops are typically under 0.5 yd³)

Special Considerations

Climate Impact

Hot Weather (>85°F):

• Ready-mix can add retarders for extended working time
• Bagged concrete sets faster—less working time per batch
• Multiple bag batches create visible seams in heat

Cold Weather (<50°F):

• Ready-mix can include accelerators or heated water
• Bagged concrete is harder to mix properly in cold
• Smaller batches lose heat quickly

Quality Control

Bagged Concrete:

• Quality varies batch to batch (water ratio consistency)
• Cold joints between batches create weak points
• Difficult to achieve professional finish

Ready-Mix:

• Consistent quality throughout entire pour
• Meets ASTM standards and building codes
• Professional testing available (slump, strength)

Structural Applications

For load-bearing elements (foundations, structural slabs, retaining walls), ready-mix is often required by building codes. The certified mix designs and quality control protect both you and future homeowners.

Real-World Project Examples

Example 1: Fence Post Installation (8 posts)

• Volume needed: 0.37 cubic yards
• Bagged option: 20 bags × $5 = $100
• Ready-mix option: $250-400 minimum
• Verdict: Bags save $150-300 and let you work over multiple days

Example 2: 8×10 Garden Shed Slab

• Volume needed: 1.0 cubic yard
• Bagged option: 45 bags × $5 = $225 + mixer rental $75 = $300
• Ready-mix option: $250-395 delivered
• Verdict: Similar cost, but ready-mix saves 8 hours of backbreaking labor

Example 3: 10×20 Driveway Approach

• Volume needed: 2.5 cubic yards
• Bagged option: 113 bags × $5 = $565 + mixer rental = $640
• Ready-mix option: $388-510
• Verdict: Ready-mix saves $130-250 AND eliminates cold joints

Example 4: Concrete Countertop

• Volume needed: 0.25 cubic yards
• Bagged option: 12 bags × $6 = $72 (premium countertop mix)
• Ready-mix option: $300+ (won't deliver tiny loads)
• Verdict: Bags are the only practical option

Environmental Considerations

Bagged Concrete

• Packaging waste: Paper bags (recyclable but bulky)
• Transportation: Multiple store trips in personal vehicle
• Precise quantities: Can minimize waste with exact purchases

Ready-Mix

• Efficient delivery: One truck trip vs. multiple car trips
• Potential waste: Must order minimum quantities
• Leftover concrete: Have a plan (small forms, fill holes, etc.)

Decision Framework

Use this simple flowchart to choose:

1. Calculate volume needed (use our calculator above)
2. Under 0.5 yards? → Bagged concrete (clear savings)
3. 0.5-1.0 yards? → Consider your time value:
   • Have time/energy and want to save money? → Bags
   • Value convenience and quality? → Ready-mix
4. Over 1.0 yards? → Ready-mix (better cost, time, quality)
5. Structural/code-required? → Ready-mix (may be mandatory)
6. No vehicle access? → Bags (no delivery needed)

Final Recommendation

The math is clear, but your decision should weigh three factors equally:

• Material cost (objective numbers)
• Time value (subjective, but real)
• Quality needs (long-term performance)

For small projects under 0.5 yards, bagged concrete is unbeatable—you save money and gain scheduling flexibility. For anything approaching 1 yard or more, ready-mix delivers better value when you account for time, labor, and final quality.

Don't make the mistake of choosing bags for a 2-yard project thinking you'll save $100. You'll spend an entire weekend mixing 90 bags, risk cold joints compromising strength, and likely end up with sore muscles and regret. Sometimes the "expensive" option is actually the bargain.

Use our calculators above to determine your exact volume, then make an informed choice based on total cost—including your time, energy, and the value of professional-quality results.