Instantly calculate how many 40 lb, 60 lb, or 80 lb bags of Quikrete or Sakrete you need for any concrete project — slabs, driveways, footings, post holes, steps & more.
A cement bags calculator for the USA helps homeowners, contractors, and DIYers determine exactly how many 40 lb, 60 lb, or 80 lb bags of premixed concrete — such as Quikrete 5000, Quikrete Fast-Setting, or Sakrete High Strength — to purchase for any project. Simply enter your project dimensions in feet and inches, choose your mix type, select your preferred bag size, and this free tool instantly calculates bags needed, cubic yardage, and estimated material cost based on current US retail pricing — so you never run short or overbuy on your next concrete pour.
🧱 Cement Bags Calculator — USA
Enter your project dimensions to calculate bags needed, cubic yards & estimated cost.
Ideal for patios, walkways, and general slabs. 4,000 PSI.
Slab 4 in · Driveway 6 in · Footing 8–12 in · Post hole 12 in
Bags of Concrete Required
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Including waste factor
📋 Project Summary
💵 Estimated Material Cost
📐 Concrete Slab Cross-Section — Layer Guide & Bag Coverage
Finished / Broomed Surface
Concrete Slab — 4 in. (Standard) Portland Cement · Sand · Aggregate · Water
🪨 4 in. Compacted Gravel Sub-Base (Crushed Stone / Class II)
In the United States, premixed concrete bags are the most convenient way to handle small to medium concrete projects without ordering a ready-mix truck. Brands like Quikrete, Sakrete, and Rapid Set combine Portland cement, sand, and aggregate in a single bag — all you need to add is water. The number of bags you need depends on three things: the volume of your pour, the bag size you choose (40 lb, 60 lb, or 80 lb), and a waste factor to account for spillage, uneven subgrades, and mixing losses.
🔵 US Standard Bag Coverage at a Glance
An 80 lb bag of Quikrete covers approximately 0.60 cubic feet of finished concrete. A 60 lb bag covers 0.45 cu ft, and a 40 lb bag covers 0.30 cu ft. To find cubic feet, multiply Length (ft) × Width (ft) × Depth (in) ÷ 12. Always add at least 10% overage.
🏠 80 lb Bag (Most Popular)
The 80 lb Quikrete or Sakrete bag is the most cost-effective option for most projects. It covers 0.60 cu ft and retails for approximately $8–$10 at Home Depot, Lowe's, or Menards. Ideal for footings, slabs, and post holes.
🧑🔧 60 lb Bag (DIY-Friendly)
The 60 lb bag is popular with homeowners who need a manageable weight when mixing by hand. Covers 0.45 cu ft and costs around $6–$8. Great for smaller pours, repairs, and raised garden beds with concrete borders.
🪶 40 lb Bag (Lightweight)
The 40 lb lightweight bag is ideal for tight spaces, repairs, and users who cannot carry heavier bags. Covers 0.30 cu ft and costs $5–$7. Commonly used for stepping stone forms, small patch repairs, and anchor bolts.
How to Calculate Cement Bags for Any Project
Calculating how many cement bags you need is a two-step process: first find your total cubic footage, then divide by the coverage per bag. The formula below applies to standard rectangular pours such as slabs, walkways, driveways, and strip footings.
Bags Needed = CEIL[ Volume (cu ft) ÷ Coverage per bag × Waste Factor ]
80 lb bag → 0.60 cu ft | 60 lb bag → 0.45 cu ft | 40 lb bag → 0.30 cu ft
Example: 10 ft × 10 ft × 4 in slab = 33.3 cu ft → 56 × 80 lb bags (+10% waste)
⚠️ Always Round Up — Never Run Short
Concrete begins to set within 30–60 minutes of mixing. Running out mid-pour creates cold joints that compromise structural integrity. Always purchase at least one extra bag beyond your calculation. Unopened bags can typically be returned to Home Depot or Lowe's within 90 days.
US Cement Bag Coverage & Cost Reference Table
The table below provides a quick-reference guide to how many bags of each size are needed per cubic yard (27 cu ft) of concrete, along with approximate 2025 retail prices at major US home improvement stores.
Bag Size / Product
Coverage (cu ft)
Bags per Cu Yd
Approx. Price (2025)
Best For
Strength
80 lb — Quikrete 5000
0.60 cu ft
45 bags
$8.50 – $10.00
Slabs, footings, driveways
5,000 PSI
80 lb — Quikrete Concrete Mix
0.60 cu ft
45 bags
$7.98 – $9.50
General purpose pours
4,000 PSI
60 lb — Quikrete
0.45 cu ft
60 bags
$6.50 – $8.00
DIY, medium projects
4,000 PSI
40 lb — Quikrete
0.30 cu ft
90 bags
$5.00 – $6.50
Small patches, repairs
4,000 PSI
50 lb — Fast-Setting (Quikrete)
0.375 cu ft
72 bags
$9.00 – $11.00
Post holes, mailboxes
4,000 PSI
80 lb — Sakrete High Strength
0.60 cu ft
45 bags
$8.00 – $9.50
Structural, driveways
5,000 PSI
80 lb — Quikrete 5000
Coverage0.60 cu ft
Bags per Cu Yd45 bags
Price (2025)$8.50 – $10.00
Best ForSlabs, footings, driveways
Strength5,000 PSI
80 lb — Quikrete Concrete Mix
Coverage0.60 cu ft
Bags per Cu Yd45 bags
Price (2025)$7.98 – $9.50
Best ForGeneral purpose pours
Strength4,000 PSI
60 lb — Quikrete
Coverage0.45 cu ft
Bags per Cu Yd60 bags
Price (2025)$6.50 – $8.00
Best ForDIY, medium projects
Strength4,000 PSI
40 lb — Quikrete
Coverage0.30 cu ft
Bags per Cu Yd90 bags
Price (2025)$5.00 – $6.50
Best ForSmall patches, repairs
Strength4,000 PSI
50 lb — Fast-Setting (Quikrete)
Coverage0.375 cu ft
Bags per Cu Yd72 bags
Price (2025)$9.00 – $11.00
Best ForPost holes, mailboxes
Strength4,000 PSI
80 lb — Sakrete High Strength
Coverage0.60 cu ft
Bags per Cu Yd45 bags
Price (2025)$8.00 – $9.50
Best ForStructural, driveways
Strength5,000 PSI
Concrete Mix Types & When to Use Each
Choosing the right premixed concrete product for your project ensures adequate strength, workability, and cure time. Quikrete and Sakrete both offer several formulations suited to different applications across the USA.
🏗️
Quikrete Concrete Mix (General)
The all-purpose 4,000 PSI concrete mix. Suitable for slabs 2 inches or thicker, walkways, steps, patios, and non-structural footings. Available in 40, 60, and 80 lb bags at all major retailers.
💪
Quikrete 5000 (High Strength)
A 5,000 PSI mix that reaches working strength in 24–28 hours. Best for driveways, footings, and slabs under heavy loads. Available in 80 lb bags only at Home Depot.
⚡
Fast-Setting Concrete Mix
Sets in 20–40 minutes without pre-mixing — just pour dry into the hole and add water. Used exclusively for post holes and fence posts. Do not use for flat pours.
🧱
Mortar Mix (Type S / Type N)
Used for laying bricks, blocks, and stone — not for poured concrete. Type S is structural; Type N is general-use mortar for above-grade applications.
🏚️
Sand / Topping Mix
Fine-textured mix without coarse aggregate for patching and resurfacing. Not suitable for structural pours. Applied 1/2 to 2 inches thick to repair damaged surfaces.
🌡️
Crack-Resistant Mix (Fiber)
Contains synthetic fiber reinforcement to reduce plastic shrinkage cracking. Ideal for driveways and garage floors exposed to freeze-thaw cycles in northern US states.
Tips for Buying & Mixing Cement Bags in the USA
Getting the best results from bagged concrete requires proper planning, measuring, and mixing technique. Whether you are a first-time DIYer or an experienced contractor, these US-specific tips will help you avoid the most common mistakes on your next concrete project.
✅ Pro Tips for a Perfect Pour
Always compact and level your subgrade before pouring. Use a hand tamper on a gravel base for slabs. In hot weather (above 90°F), mist the subgrade before pouring and cure the slab with plastic sheeting. In cold weather (below 40°F), use warm water and cover the finished pour with insulating blankets overnight.
Buy bags from a single batch — mixing bags from different production batches can cause slight color and strength variations in your finished concrete.
Store bags off the ground — even one inch of moisture from a damp floor can cause cement to partially hydrate inside the bag, making it unusable.
Use a paddle mixer drill for 5 bags or fewer. For larger projects, rent a drum mixer from Home Depot or Sunbelt Rentals for around $35–$50/day.
Add water gradually — the instructions call for 3 quarts per 80 lb bag, but add 80% first, then adjust until you reach a stiff but workable consistency.
Cut control joints at intervals of 2–3× the slab thickness in feet (every 8–10 ft for a 4-inch slab) to control where cracks occur naturally.
Frequently Asked Questions — Cement Bags USA
How many 80 lb bags of concrete do I need for a 10×10 slab?+
For a 10×10 ft slab at 4 inches thick, you need approximately 56 bags of 80 lb concrete (including 10% waste). The calculation: 10 × 10 × (4/12) = 33.3 cu ft ÷ 0.60 cu ft per bag = 55.6, rounded up to 56 bags. At 6 inches thick, you would need 84 bags. Always round up and buy one extra bag for contingency.
What is the difference between Quikrete and Sakrete?+
Both are premixed bagged concrete products. Quikrete is the largest US manufacturer, sold primarily at Home Depot. Sakrete is second-largest, typically at Lowe's and Ace Hardware. Their standard 80 lb bags have nearly identical coverage (0.60 cu ft) and strength (4,000–5,000 PSI). The choice usually comes down to store preference and current pricing.
How many bags of concrete do I need for a 4-inch 20×20 ft driveway?+
A 20×20 ft driveway at 4 inches thick requires approximately 222 × 80 lb bags with 10% waste. At ~$9/bag that is $2,000 in materials alone. At this volume, it is far more economical to order a ready-mix concrete truck — typically $150–$200/yard delivered, saving you roughly $1,600 and hours of mixing labor.
How many 80 lb bags are in a cubic yard of concrete?+
One cubic yard = 27 cubic feet. Since an 80 lb bag covers 0.60 cu ft, you need 45 bags per cubic yard. For 60 lb bags: 60 bags/yard. For 40 lb bags: 90 bags/yard. At ~$9 per 80 lb bag, one cubic yard of bagged concrete costs roughly $405 — vs. $150–$200 for ready-mix. Bagged concrete is most economical for pours under 0.5 cubic yards.
How do I use Quikrete Fast-Setting for a fence post?+
Dig a hole 1/3 the post length deep and 3× the post diameter wide. Place the post plumb, pour dry Fast-Setting mix directly into the hole (no pre-mixing), add about 1 gallon of water per 50 lb bag, and brace for 20–40 minutes until set. One 50 lb bag typically handles one standard post in a 10-inch diameter, 2-foot deep hole.
What PSI concrete do I need for a driveway in the USA?+
For a residential driveway with passenger vehicles, ACI recommends a minimum of 3,500 PSI. Most contractors use 4,000 PSI as standard. For driveways in freeze-thaw climates (northern states) or with heavy vehicles, use 4,500–5,000 PSI with air entrainment. Quikrete 5000 or Sakrete High Strength are ideal for northern US driveways.
How long does bagged concrete take to cure in the USA?+
Standard Quikrete or Sakrete follows this timeline: 24 hours — initial set, light foot traffic; 3 days — remove forms, no vehicle traffic; 7 days — ~70% strength, light vehicles; 28 days — full 4,000 PSI design strength. Keep the slab moist for the first 7 days by misting or covering with plastic sheeting.
How thick should a concrete garage slab be?+
A residential garage slab should be a minimum of 4 inches thick for standard passenger vehicles, with a 6-inch thickened edge perimeter. For heavier vehicles like pickup trucks, RVs, or workshops with heavy equipment, 6 inches is the recommended minimum. Most US building codes based on IBC require a minimum 3.5 inches for garage slabs on grade.
What is the difference between Portland cement and premixed bags?+
Portland cement (94 lb bags, ~$15–$18 each) is just the binding ingredient and must be combined with sand and aggregate separately. Premixed bags (Quikrete/Sakrete) already include everything — just add water. Portland cement is used by contractors who buy sand and gravel in bulk for large projects where mixing your own is more economical at scale.
Do I need gravel under a concrete slab in the USA?+
Yes — a 4-inch compacted gravel base (crushed stone or Class II base) is required under concrete slabs in most US applications. Gravel improves drainage, prevents frost heave in northern states, and provides a stable base. Without it, slabs can crack, settle, and heave. ACI 302.1R requires a minimum 4-inch sub-base for residential slabs on grade.
How many bags for a 12×12 patio at 4 inches thick?+
Volume = 12 × 12 × (4/12) = 48 cu ft. Divided by 0.60 cu ft per 80 lb bag = 80 bags. With 10% waste: 88 × 80 lb bags, costing approximately $770–$880. At 1.78 cubic yards, you are near the threshold where ordering 2 yards of ready-mix (~$350–$450 delivered) may be cheaper and far less labor-intensive.
Is it cheaper to use bagged concrete or order a ready-mix truck?+
Bagged concrete is cheaper for pours under 0.5 cubic yards (about 13 cu ft). For larger projects, ready-mix at $150–$200/yard is far less than the ~$405/yard for 80 lb bags. The crossover point is typically around 1 cubic yard. A ready-mix truck also saves significant labor — mixing 45 bags by hand is exhausting. For anything over a 10×10 slab at 4 inches, consider calling a local ready-mix supplier.
Trusted guides, standards, and product references for your next concrete project.
📘
Quikrete Product Guide
Official Resource
Official Quikrete product selector, data sheets, coverage charts, and project guides for all 40/60/80 lb concrete, mortar, and specialty mix products sold across the USA.
The American Concrete Institute's ACI 318 Building Code Requirements for Structural Concrete — the authoritative standard for all concrete design and construction in the USA.
Shop and compare all Quikrete, Sakrete, and store-brand concrete bag products at Home Depot online, with current pricing, coverage specs, and in-store availability by zip code.