Parameter input guide
Set dimensions and cube strength, then enter practical bar counts and diameters in up to three layers. Use independently checked factored actions. Hover, focus or tap the information controls for units and source assumptions.
Worked source example
A 600 × 750 mm beam, 50 mm cover and two groups of 5T25 provides 4,908.739 mm². Source M = 993 kN·m gives source d = 675.5 mm and required steel 3,752.531 mm². The actual layered centroid differs and is shown separately. These benchmark values test the port, not compliance.
Scope and limitations
The source lever-arm and shear-factor expressions contain material issues. Their values are displayed as comparisons and cannot establish a design pass. SLS, global analysis, anchorage, laps, punching and current-code detailing are not assessed. Do not equate a reinforcement demand ratio with moment capacity utilisation.
Engineering disclaimer
These tools assist engineering calculations and do not replace professional engineering judgement or independent verification. Confirm inputs, units, assumptions, applicable standards and every governing project check with a suitably qualified engineer before safety-critical use. Software and reference workbooks may contain errors or omissions. A disclaimer does not guarantee immunity from legal liability. Read the Terms / Engineering Disclaimer.