Concrete DrumCapacity Calculator USA — Ready-Mix & Mixer
Instantly calculate the usable capacity of any concrete mixer drum — ready-mix transit trucks or portable jobsite mixers. Find loads needed for your project, bags per batch, and ASTM C94 compliance status.
8–10
Cu Yd — Standard Ready-Mix Truck Capacity
60%
Max Drum Fill Factor — ASTM C94 Standard
300
Max Revolutions Before Discharge (ASTM C94)
90
Min Discharge Time — Ready-Mix (Minutes)
🚛 Ready-Mix Transit Truck🔄 Portable Drum Mixer🏗️ Stationary Plant Mixer🧱 Bag Mix / DIY Drum📦 Number of Loads💰 Delivery Cost Estimate
A concrete drum capacity calculator for the USA helps contractors, project managers, and DIYers determine the exact usable volume of a concrete mixer drum — whether it's a ready-mix transit truck drum (8–11 cubic yards) or a portable jobsite mixer (1.5–12 cubic feet). Per ASTM C94 — the governing US standard for ready-mixed concrete — a drum should never exceed 63% of its geometric volume to ensure proper mixing action. This free tool calculates usable capacity, number of truck loads or mixer batches needed for any pour volume, estimated delivery cost, and ASTM C94 compliance status.
🥁 Concrete Drum Capacity Calculator — USA
Select drum type, enter capacity or dimensions, and project volume to calculate loads needed and compliance.
Standard transit trucks carry 8–10 yd³. ASTM C94 max load = 63% of drum volume.
Most US residential trucks carry 8 yd³; commercial trucks 9–10 yd³.
Portable mixers should be loaded to 60% of rated drum capacity.
ASTM C94 limits ready-mix drums to 63% of geometric volume for proper mixing.
Usable Concrete (60% Fill)Drum Shell / StructureHeadspace / Mixing ZoneAbove Fill Line (Air)
What Is Concrete Drum Capacity & Why Does It Matter in the USA?
The concrete drum capacity refers to the actual usable volume of mixed concrete that can be produced or transported in a single rotation of a concrete mixer drum. For ready-mix transit trucks, drum capacity determines how many cubic yards can be delivered per trip. For portable jobsite mixers, it determines how many batches are required to complete a pour. Per ASTM C94 — the definitive US standard for ready-mixed concrete — a drum must never be loaded beyond 63% of its geometric (total) volume to ensure proper mixing action and uniform concrete quality.
🔵 ASTM C94 — US Standard for Ready-Mix Drum Capacity
ASTM C94 specifies that the rated capacity of a ready-mix truck drum is the maximum batch size that allows proper mixing. Rated capacity = 63% of geometric drum volume. A drum with a geometric volume of 16 cubic yards has a rated capacity of approximately 10 cubic yards. Overloading above 63% prevents the drum blades from lifting and tumbling the concrete properly, resulting in segregation, poor homogeneity, and mix that fails ACI 301 acceptance criteria.
🚛 Ready-Mix Transit Truck Drum
The most common concrete delivery method in the USA. Standard trucks carry 8–10 cubic yards per load. The rotating drum keeps concrete agitated during transport at 1–2 RPM. Mixing speed is 6–18 RPM per ASTM C94. Must be discharged within 90 minutes or 300 revolutions (whichever comes first) to maintain quality.
🔄 Portable Drum Mixer (Jobsite)
Tilting barrel mixers ranging from 1.5 to 18 cubic feet are used for small to medium DIY and contractor pours. Common sizes are 3.5 cu ft (1-bag) and 6 cu ft (2-bag). Should be filled to 60% of drum capacity for proper mixing. Ideal for projects under 1 cubic yard where ready-mix is impractical.
🏗️ Stationary / Plant Mixer
Central mix plants (ASTM C685) use large stationary drum or pan mixers to batch and fully mix concrete before loading into trucks. Drum capacities range from 1 to 12 cubic yards per batch. Produces more consistent concrete than transit mix but requires the plant to be within close proximity to the job site for proper delivery timing.
How to Calculate Concrete Drum Capacity & Loads Needed
Calculating drum capacity and number of loads involves three steps: determine the geometric drum volume, apply the ASTM C94 fill factor to get usable capacity, then divide your total project volume (including waste factor) by the usable capacity per load. This tells you exactly how many truck loads or mixer batches to order.
⚠️ Never Overload a Concrete Drum — ASTM C94 Maximum is 63%
Overloading a ready-mix drum beyond 63% of geometric volume is a violation of ASTM C94 and can result in concrete that fails ACI 301 strength and uniformity acceptance tests. The excess concrete at the back of the drum cannot be properly lifted and tumbled by the mixing blades, causing aggregate segregation, paste stratification, and inconsistent slump throughout the load. On the jobsite, overloaded drums are also a leading cause of truck tip-overs on sloped access roads — a serious safety hazard regulated by OSHA 29 CFR 1926 Subpart Q.
Quick-reference guide to standard US ready-mix truck drum capacities, usable loads at ASTM C94 fill factors, and approximate 2025 delivery costs per load for major US metro areas. Costs are for standard 4,000 PSI general-purpose mix delivered within 10 miles of the batch plant.
Truck / Drum Type
Rated Capacity
Usable @ 60%
Usable @ 63%
Est. Cost / Load (2025)
ASTM C94 Status
Small Truck (Short Load)
6 cu yd
5.76 cu yd (est.)
6.0 cu yd
$900 – $1,200
Short Load Fee
Mid-Size Transit Truck
7 cu yd
7.0 cu yd
7.0 cu yd
$1,050 – $1,400
Compliant
Standard Residential Truck
8 cu yd
8.0 cu yd
8.0 cu yd
$1,200 – $1,600
Compliant
Standard Commercial Truck
9 cu yd
9.0 cu yd
9.0 cu yd
$1,350 – $1,800
Compliant
Full-Size Transit Truck
10 cu yd
10.0 cu yd
10.0 cu yd
$1,500 – $2,000
Compliant
Large Transit Truck
10.5 cu yd
10.5 cu yd
10.5 cu yd
$1,575 – $2,100
Compliant
Maximum Capacity Truck
11 cu yd
11.0 cu yd
11.0 cu yd
$1,650 – $2,200
Compliant
Small Truck — 6 Cu Yd (Short Load)
Rated Capacity6 cu yd
Usable @ 60%5.76 cu yd
Est. Cost$900 – $1,200
StatusShort Load Fee
Standard Residential Truck — 8 Cu Yd
Rated Capacity8 cu yd
Usable @ 60%8.0 cu yd
Est. Cost$1,200 – $1,600
StatusCompliant
Standard Commercial Truck — 9 Cu Yd
Rated Capacity9 cu yd
Usable @ 60%9.0 cu yd
Est. Cost$1,350 – $1,800
StatusCompliant
Full-Size Transit Truck — 10 Cu Yd
Rated Capacity10 cu yd
Usable @ 60%10.0 cu yd
Est. Cost$1,500 – $2,000
StatusCompliant
Maximum Capacity Truck — 11 Cu Yd
Rated Capacity11 cu yd
Usable @ 60%11.0 cu yd
Est. Cost$1,650 – $2,200
StatusCompliant
Portable Concrete Mixer Drum Capacity — USA Jobsite Guide
Portable drum mixers are the go-to solution for projects under 1 cubic yard where a ready-mix truck order is impractical or too costly. In the United States, the most popular portable mixer sizes are the 3.5 cu ft (1-bag) and 6 cu ft (2-bag) models available at Home Depot, Lowe's, and equipment rental centers nationwide. Understanding usable batch capacity is critical for planning how many 80 lb bags of Quikrete or Sakrete you need per batch and how many total batches your project requires.
1.5 cu ft drum (½-bag mixer) — Usable capacity at 60%: ~0.9 cu ft per batch. Holds approximately half an 80 lb bag. Good for small patch repairs, stepping stones, and anchor bolts. Weighs about 65 lbs — easily moved by one person.
3.5 cu ft drum (1-bag mixer) — Usable capacity: ~2.1 cu ft per batch. Holds one 80 lb bag plus water. The most popular DIY concrete mixer in the USA. Available for rent at Home Depot for approximately $45/day. Takes about 3–4 minutes per batch.
6 cu ft drum (2-bag mixer) — Usable capacity: ~3.6 cu ft per batch. Holds two 80 lb bags. Common on light contractor jobs. Electric or gas powered. Rental rate approximately $60–$75/day. Requires GFCI protection on electric models per OSHA 1926.404.
9 cu ft drum (3-bag mixer) — Usable capacity: ~5.4 cu ft per batch. Popular for fence post projects, driveways in sections, and foundation work. Typically towable or skid-mounted. Rental approximately $80–$110/day.
12–18 cu ft drum (4–6 bag mixer) — Usable capacity: ~7.2–10.8 cu ft per batch. Heavy-duty contractor mixers for large pours completed in multiple batches. Often diesel powered for remote sites without electrical power.
🔵 Ready-Mix vs. Portable Mixer — Which Is More Cost-Effective?
For pours under 1 cubic yard, bagged concrete mixed in a portable drum is typically cheaper ($120–$200 in materials vs. $600–$900 minimum ready-mix short-load charge). For pours between 1–3 cubic yards, it depends on crew size, time constraints, and access. For pours over 3 cubic yards, ready-mix is almost always more cost-effective and produces more consistent, higher-quality concrete than field-mixed batches. Most ACI-recommended structural concrete specifications require ready-mix for any pour over 2 cubic yards.
Frequently Asked Questions — Concrete Drum Capacity Calculator USA
How many cubic yards does a standard concrete truck drum hold in the USA?+
A standard US ready-mix transit truck carries 8–10 cubic yards of concrete per load. The most common residential delivery is 8 cubic yards; commercial trucks typically carry 9–10 cubic yards. The maximum permitted by most US states and ASTM C94 is 10–11 cubic yards. Most ready-mix companies charge a short-load fee (typically $15–$25 per cubic yard under the minimum) for orders less than 5–7 cubic yards, making it cost-effective to order a full load when possible.
What is the ASTM C94 maximum fill for a concrete drum?+
Per ASTM C94 Section 9.1, the maximum batch volume for a transit mix drum is 63% of the drum's gross geometric volume. For a drum with a 16 cubic yard geometric volume, the maximum batch is approximately 10 cubic yards. This 63% limit exists to ensure the concrete is properly lifted and tumbled by the internal mixing blades during transport. Loading beyond 63% reduces mixing efficiency, causes aggregate segregation, and can result in concrete that fails ACI 301 uniformity and slump acceptance tests at the point of discharge.
How long can concrete stay in a drum before it must be discharged?+
ASTM C94 specifies that concrete must be discharged from the drum within 90 minutes of first adding water to the mix OR before the drum has completed 300 revolutions — whichever comes first. In hot weather (above 90°F), many US ready-mix companies and project specifications reduce this to 60 minutes, as high temperatures accelerate cement hydration and reduce workability rapidly. After 90 minutes, concrete typically begins to stiffen beyond acceptable placement slump and should not be placed in structural applications per ACI 301-16 Section 7.3.
How do I calculate how many batches a portable mixer needs for my project?+
First calculate your project volume in cubic feet: Length (ft) × Width (ft) × Depth (in) ÷ 12 × 1.10 (10% waste). Then divide by the usable capacity of your mixer drum (rated size × 60%). For example: a 10×10 ft patio at 4 inches needs 33.3 cu ft × 1.10 = 36.7 cu ft total. With a 3.5 cu ft mixer at 60% fill = 2.1 cu ft per batch: 36.7 ÷ 2.1 = 18 batches, requiring approximately 18 × 1 bag = 18 bags of 80 lb Quikrete. At 4 minutes per batch, plan for 1.5–2 hours of mixing time plus placement.
What is a "short load" fee for ready-mix concrete in the USA?+
A short load fee is a surcharge charged by US ready-mix companies when a customer orders less than the minimum full-truck quantity — typically 7–10 cubic yards depending on the supplier. Short load fees typically range from $15 to $30 per cubic yard below the minimum. For example, if a supplier's minimum is 8 yards at $150/yard and you order 5 yards, you may be charged $150/yd × 5 yd + $25/yd × 3 yd shortfall = $825 total. Always ask your supplier about short-load minimums before ordering. For very small orders (under 3 yd³), a portable mixer and bagged concrete is usually more economical.
How many 80 lb bags of concrete does one cubic yard equal?+
One cubic yard (27 cubic feet) of concrete requires approximately 45 bags of 80 lb Quikrete or Sakrete (at 0.60 cu ft per bag coverage). This equates to approximately 3,600 lbs (1.8 tons) of bagged product — not including water. At approximately $9 per 80 lb bag in 2025, one cubic yard of bagged concrete costs about $405 in materials alone, compared to approximately $150–$175 per cubic yard for ready-mix delivered. For pours larger than 2 cubic yards, ready-mix is clearly more cost-effective.
Does drum rotation speed affect concrete quality in a ready-mix truck?+
Yes — drum rotation speed is critical and regulated by ASTM C94. Ready-mix drums rotate at two speeds: mixing speed (6–18 RPM) at the batch plant to blend ingredients, and agitating speed (1–2 RPM) during transit to prevent settling without over-working the mix. Running the drum at mixing speed for the entire transit causes excess heat generation from friction, accelerates cement hydration, and can cause the concrete to lose slump and workability before arrival. ASTM C94 Table 1 specifies exact RPM ranges for mixing vs. agitating modes for each drum size and concrete type.
Official ASTM, ACI, and industry standards for ready-mix truck drum capacity, mixing requirements, and concrete delivery in the United States.
🔬
ASTM C94 — Ready-Mixed Concrete
Industry Standard
ASTM C94 is the primary US standard governing ready-mixed concrete specifications, drum capacity limits (63% of geometric volume), mixing requirements, delivery time limits (90 minutes/300 revolutions), and acceptance testing at the point of discharge.
ACI 304R provides comprehensive guidance on measuring, mixing, transporting, and placing concrete in the USA, including drum mixer fill factors, batch size optimization, portable mixer best practices, and field quality control procedures.
The National Ready Mixed Concrete Association (NRMCA) is the primary US industry organization for ready-mix concrete producers. Their resources cover truck drum specifications, delivery guidelines, mix design data, and producer certification programs across all 50 states.