You know the number. The plan says 8 yards, the ticket says 6,116 litres, or the store shelf sells 80-pound bags. This converter moves one known concrete quantity across the volume, weight, and bag units without remeasuring anything.
How do you convert a concrete quantity?
Enter the quantity once and pick its unit. The converter prints every volume equivalent, then adds weight and bag numbers only from the assumptions you enter. Volume numbers are exact by definition. Weight and bag numbers depend on a stated unit weight and a stated yield, and the converter has no defaults for either.
Volume equivalents = quantity × exact unit factors
Weight = volume × stated unit weight
Whole bags = ceiling(volume ÷ stated yield per bag)
What does the converter need from you?
| Input | What to enter | Why it matters |
|---|---|---|
| Quantity and unit | One known pour quantity, in yd³, ft³, m³, or litres | Sets the starting side of the conversion |
| Unit weight (optional) | The mix's value in lb/ft³ or kg/m³ | Unlocks weight outputs; blank keeps them off rather than guessing |
| Yield per bag (optional) | The product label's mixed yield per bag | Unlocks bag counts; bag mass alone cannot set the count |
| Bag label (optional) | Example: 80-lb bag | Recorded beside the result so the number stays checkable |
The unit-weight and yield fields start blank and stay blank. A bag number without a product name is not a quantity.
Which conversions are exact?
Cubic yards, cubic feet, cubic metres, and litres are linked by definitions, so every converter gives the same answers. The converter moves every entry into cubic metres at full precision, then displays up to 3 decimal places.
| Relationship | Constant used | Where it applies |
|---|---|---|
| 1 yd³ = 27 ft³ | Exact | Imperial volume entries |
| 1 m³ = 1,000 L | Exact | Metric volume entries |
| 1 yd³ = 0.764554857984 m³ | NIST Handbook 44 value | Cross-system conversions |
| 1 ft³ = 0.028316846592 m³ | NIST SI Guide value | Cross-system conversions |
| 1 ft³ = 28.316846592 L | Derived from 1 ft³ and 1 L | Imperial to metric display |
| 1 short ton = 2,000 lb; 1 metric tonne = 1,000 kg | Exact | Weight entries and outputs |
| 1 lb/ft³ = 16.01846337396014 kg/m³ | Derived from 1 lb and 1 ft³ | Unit-weight entries |
Switching the unit system converts the entered quantity and any entered assumptions to the new system's primary units, clears the result, and requires a fresh calculation.
Worked imperial example
A plan calls for 8 yd³ of concrete. The mix record states 150 lb/ft³ as a planning nominal, and the selected 80-lb bag product lists 0.60 ft³ of mixed yield per bag.
- Volume in cubic feet: 8 × 27 = 216 ft³.
- Volume in cubic metres: 216 × 0.028316846592 = 6.116436463872 m³.
- Volume in litres: 216 × 28.316846592 = 6,116.438863872 L.
- Weight: 216 × 150 = 32,400 lb, or 16.2 U.S. short tons.
- Bags: 216 ÷ 0.60 = 360.0, so 360 whole bags.
Converted result: 216 ft³, 6.116 m³, 6,116.439 L, 32,400 lb (16.2 short tons), and 360 bags. The 150 lb/ft³ and 0.60 ft³ per bag are stated fixtures for this example, not defaults the converter supplies.
Worked metric example
A ticket shows 5 m³. The mix record states 2,400 kg/m³, and the product label states 17 L of mixed yield per bag.
- Weight: 5 × 2,400 = 12,000 kg, or 12 metric tonnes.
- Volume: 5 × 1.3079506193 = 6.53975309655 yd³; 5 × 35.314666721 = 176.573333605 ft³.
- Bags: 5,000 ÷ 17 = 294.1176…, so 295 whole bags.
- Purchased mixed volume: 295 × 17 = 5,015 L.
Converted result: 12,000 kg, 6.540 yd³, 176.573 ft³, and 295 bags. The ceiling step matters: you cannot buy 0.12 of a bag.
Which yield number should you enter?
Read the product label for the mix you will actually buy. QUIKRETE's Concrete Mix No. 1101 data sheet lists approximate yields of 0.60 ft³ (17 L) for an 80-lb bag, 0.45 ft³ (12.7 L) for a 60-lb bag, and 0.30 ft³ (8.5 L) for a 40-lb bag, stated as approximate. Other brands and products list their own yields, and the label guide explains why the yield, not the bag mass, controls the count.
Write 0.60 ft³ per 80-lb bag, QUIKRETE 1101, label date, rather than 0.60 alone. A number without its source and unit cannot be checked later, and it cannot be reused for a different product.
Common conversion mistakes
- Entering feet where inches belong: an inch thickness must be divided by 12 before it becomes feet.
- Using a bag mass as a yield; mass tells you what the bag weighs, not what it produces.
- Copying a hardcoded 45-bags-per-yard table onto a product with a different label yield.
- Treating a weight number as exact when the unit weight was never stated.
- Mixing a loose-material density with placed concrete; only the mix's unit weight belongs here.
- Rounding the quantity before converting, then comparing the result with the ticket.
- Adding waste or allowance inside the conversion; the ordering guide adds it on its own line, separate from the conversion and the rounding.
The common mistakes guide and the worked example walk through these errors with site context.
What the converter does not do
The converter changes units through your stated assumptions. It does not measure the pour, choose the mix, set an allowance, convert between loose and compacted states, or add swell, shrinkage, waste, or contingency. Those are separate calculations with separate evidence.
It does not set a truck load. Ready-mix plants sell by the cubic yard in the US, but the minimum load, short-load fee, and batch increment are the plant's terms; confirm them when you book. The ordering guide covers the steps that follow a conversion, and the ticket-reading guide shows how to pull a verified quantity from a delivery ticket.
For quantities that start from site dimensions rather than a known volume, use the Concrete Slab Calculator or the Concrete Bags Calculator, which measure geometry first.
Sources and scope
- NIST Handbook 44 (2026), Appendix C: cubic-foot, cubic-yard, litre, and cubic-metre relationships; accessed 19 October 2026.
- NIST Guide to the SI, Appendix B: cubic-foot, cubic-inch, and cubic-metre conversion factors; accessed 19 October 2026.
- The QUIKRETE Companies, QUIKRETE Concrete Mix No. 1101 SPEC-DATA: stated approximate yields of 0.60 ft³ (80-lb bag), 0.45 ft³ (60-lb bag), and 0.30 ft³ (40-lb bag); applies to that product only; accessed 19 October 2026.
- ASTM International, ASTM C94/C94M: the producer furnishes a delivery ticket for each batch; accessed 19 October 2026.
Source scope: NIST supports the stated volume conversions. QUIKRETE supports the worked-example yields as product-specific fixtures, not defaults. ASTM supports the delivery-ticket claim. Project drawings, specifications, the supplier record, product labels, local weights-and-measures rules, and responsible people control the accepted unit weight, yield, and final project quantity.
Review note: Calculation logic and independent automated fixtures passed internal review. Saleem Sial is the research and editorial owner. Waseem Sial, External Reviewer and Engineer, remains listed for ongoing external review; no completed external-review date is claimed.
