SettingsSettings for this calculationUS
The total mass of all ingredients in the batch.
Sum of cement, water, aggregates, and admixture masses.
The batch's measured unit weight, from an ASTM C138 unit weight test.
See the Concrete Unit Weight Calculator.
The volume the mix design was intended to produce.
One cubic metre is the usual metric design batch; a US mix design is written per cubic yard, which is 0.765 m³.
Relative yield
1.07 (ratio, target 1.0)
The batch produced MORE volume than designed — the mix may be under-yielding on materials relative to the design, or air content is higher than assumed.
- Actual yield
- 1.34 yd³
They open the calculator with your figures already in it
Concrete Relative Yield Calculator (ASTM C138): 1.07 (ratio, target 1.0) — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
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How this was calculated
Formula source(s)
- ASTM C138 relative yield: actual yield = total batch mass / measured unit weight; relative yield = actual yield / design volume (should be close to 1.0)
Inputs used
- Total Batch Mass
- 5290 lb
- Measured Unit Weight
- 146.71 pcf
- Design Batch Volume
- 1.25 yd³
Intermediate steps
- Actual yield
- 1.34 yd³
Confidence note: The batch produced MORE volume than designed — the mix may be under-yielding on materials relative to the design, or air content is higher than assumed.
What this calculation does not cover
- A relative yield of 0.96 or 1.03 tells you the batch missed its design volume; it does not tell you why. Air content, aggregate moisture, scale calibration and admixture dosage all move yield, and none of them are inputs here — this flags the symptom and leaves the diagnosis to the air meter, the moisture test and the batch records.
- This is a volume check, not an acceptance test. A batch can land at 1.00 relative yield and still fail its specified strength, slump or air content, and none of those are evaluated here.
- The total batch mass is taken as entered and never verified. It has to be the mass actually batched, with free moisture on the aggregates included — enter the mix design's SSD proportions instead of the batch ticket's real weights and the yield error is invisible to this calculation.
- One unit weight sample, one batch. Yield varies within a load and between loads, and nothing here allows for that variation, for the calibration of the measure the sample was struck off in, or for how well the sample was consolidated.
- The ±2% window used to pass or fail the result is a common working rule, not an acceptance clause — ASTM C138 gives the yield computation, not a tolerance. Whether you were delivered the volume you paid for is settled under the delivery tolerance in the purchase specification, not by this ratio.
Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Sources checked 2026-09-03 · in the site-wide review of 2026-09-06 · v1.1.1
Regulatory standards & verification citations1
- ASTM C138 relative yield: actual yield = total batch mass / measured unit weight; relative yield = actual yield / design volume (should be close to 1.0)
Which documents these citations point at
Standards referenced: ASTM C138 (ASTM International, United States).
Cite this page
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Tools and safety for this job
To place and finish concrete, erect formwork and saw-cut cured concrete. Generic types, no brands, no prices.
Protection this work requires
- Cutting or grinding concrete, masonry, screed, tile or fibre-cement board releases respirable silica: cut wet or extract at the tool, and wear a P2/N95 respirator at minimum — a nuisance dust mask does not filter it.
- Hardwood dust is a recognised carcinogen: extract at the tool and wear a P2/N95 respirator when cutting or sanding indoors.
- Wet cement and lime burn skin and eyes painlessly until the damage is done: waterproof gloves to EN 374, safety glasses whenever the mix can splash, and never kneel in wet mix in permeable trousers.
- Saws, grinders and breakers run above 85 dB, where hearing damage accumulates and does not recover: defenders or plugs for every cut, not just the long ones.
- Breakers and grinders cause permanent nerve damage: limit continuous trigger time, keep hands warm, and stop if fingers tingle or blanch.
- Boards, blocks and bagged material cause most lasting back injuries on small sites: two people or a lifter for full sheets, and never a bag on one shoulder up a ladder.
Show the 17 tools this job needsHide tools
Essential
Angle grinder
Bull float and edger
Circular saw
Claw hammer
Dust extractor or vacuum with a fine filter
Screed bar or rail
Shovel and spade
Spirit level
String line and pins
Tape measure
Wheelbarrow
Recommended
Chalk line
Cordless drill/driver
Floor or cut-off saw
Plate compactor
SDS rotary hammer
Optional
Power float
Also needed as materials: chalk refill, circular saw blades, cutting and diamond discs, diamond blades, drill and driver bits, SDS bits and chisels.
what each concrete tool is for, and the spec that decides which to buy where one does.