Concrete Sampling Rate Calculator
Enter the pour volume and the sampling rate, get the number of cube sets to make. Built for site teams planning a pour.
Enter the pour volume and the sampling rate, get the number of cube sets to make. Built for site teams planning a pour.
Enter the volume of the pour and the sampling rate from your specification, or pick a typical rate. The calculator rounds up to whole sets, applies the one-set-per-day minimum and shows how often to sample across the loads.
A set of cubes represents one sample of fresh concrete. The calculator divides the pour volume by the sampling rate and rounds up, because a part volume still needs its own sample. It then applies the minimum of one sample per mix on each day of pouring and checks the batch rule: where loads are small, the count by batches can exceed the count by volume, and the higher figure stands.
The sampling rate belongs to the project specification, not to the testing laboratory. BS EN 206 and BS 8500 set the acceptance criteria for identity testing and leave the frequency to the specifier. Where the specification states a rate, enter it. The typical rates offered are published in the Specification for Highway Works and are a reasonable planning basis when no rate has been given yet.
The Specification for Highway Works, Series 1700, Clause 1707 sets the rates below for highway structures. Each rate is one sample from the stated volume or the stated number of batches, whichever is the lesser volume, with three cubes made from each sample.
A set is the cubes made from one sample. The 28-day result is the mean of a pair of cubes, so two cubes are the minimum. A third cube tested at 7 days gives an early indication of strength gain, and extra cubes cover 56-day testing or a reserve. Sampling follows BS EN 12350-1; cubes are made and cured to BS EN 12390-2 and tested to BS EN 12390-3.
A 65 m³ ground-floor slab in reinforced concrete, poured in one day: 65 ÷ 20 = 3.25, rounded up to 4 sets. At three cubes per set that is 12 cubes, taken from roughly every third 6 m³ load so the samples are spread through the pour.
Does the calculator replace the sampling plan in my specification?
No. The specification governs. Enter its rate under “Rate set by your specification” and the calculator does the counting. The typical rates are for planning before a specification is to hand.
Why round up rather than to the nearest whole set?
Every rate is written as a volume or part of it. A pour of 21 m³ at one sample per 20 m³ needs two samples, because the final cubic metre is still concrete that no cube represents.
Who takes the samples and makes the cubes?
Either the site team or an Omega technician. Where the specification calls for independent sampling, our technicians sample to BS EN 12350-1, make and cure the cubes to BS EN 12390-2 on site, then collect them for testing.
The Omega Group (Operations) Limited is a UKAS accredited testing laboratory No. 7644. Sampling, cube making and compressive strength testing are on its schedule of accreditation. The planning figures on this page are not test results and sit outside the scope of accreditation.