A comparison between cube and cylinder strength of the concrete is required to know to get them an idea about the characteristics strengths to be used in different standards. For example, Eurocode uses the characteristic cylinder strength to represent the strength of the concrete.
But the British standard mainly uses the cube strength as characteristic strength to represent the concrete in the design formulas.
Therefore, knowing the relevant strength classes or the relationship between the structure are important.
As it appears, there is no linear relationship between the cube strenth and the cylinder strength. However, some times, it can be observed that some designers use 0.8-0.9 factor to get the relevant cylinder strength for a particular cube strength.
Now, we need not worry about any factor to calculate the relationship the characteristic stress. Eurocode 2 has given a relationship to consider when designing with that standard.
The values extracted from Table 3.1 of Eurocode 2 are shown below.
| Characteristic Cylinder Strength | Characteristic Cube strength |
| 12 | 15 |
| 16 | 20 |
| 20 | 25 |
| 25 | 30 |
| 30 | 37 |
| 35 | 45 |
| 40 | 50 |
| 45 | 55 |
| 50 | 60 |
| 55 | 67 |
| 60 | 75 |
| 70 | 85 |
| 80 | 95 |
| 90 | 105 |
The values could be applicable mostly for the Eurocode. If these values are used for any calculation based on other standards, necessary verifications shall be done.
Thus, having an idea or Comparison of cube strength and cylinder strength will help the designer to understand the designs well.