About this calculator

How-to: enter the vertical pour rate (m/hr), concrete temperature at placement, and choose the mix chemistry. We use the CIRIA / ACI 347 wall formula P = C_w · C_c · (150 + 9000·R/T), then cap it at hydrostatic pressure ρ·g·h. Result is in kPa — divide by 47.88 for psf.

Frequently asked questions

Which standard is this?

It follows the CIRIA Report 108 wall formula (widely used in the EU/UK) which is aligned with ACI 347. Both cap at hydrostatic pressure ρgH.

Why does colder concrete give higher pressure?

Cold concrete hydrates slower, so it stays fluid deeper into the pour. That's why R/T controls the formula — high pour rate, low temperature → higher pressure.

How do I use the result for tie spacing?

Multiply the pressure by the tributary area of each tie. Cross-check against the tie's working load limit with a factor of safety of 2.

What does the Concrete Formwork Pressure Calculator do?

Maximum lateral pressure on wall or column formwork from the ACI 347 / CIRIA 108 method, based on pour rate, concrete temperature and mix type. How-to: enter the vertical pour rate (m/hr), concrete temperature at placement, and choose the mix chemistry. We use the CIRIA / ACI 347 wall formula P = C_w · C_c · (150 + 9000·R/T), then cap it at hydrostatic pressure ρ·g·h. Result is in kPa — divide by 47.88 for psf.

Is the Concrete Formwork Pressure Calculator free to use?

Yes. Every calculator on Calcurly.com is free, works in your browser without sign-up, and can be embedded on your own website.

How accurate is the Concrete Formwork Pressure Calculator?

Results are calculated in real time using industry-standard formulas. Treat the output as a well-informed estimate — always cross-check with local regulations, product datasheets, or a qualified construction & building professional before committing to a purchase or a job.

What inputs does the Concrete Formwork Pressure Calculator need?

Enter values for: Pour rate (m/hr), Concrete temperature (°C), Form height (m), Element, Chemistry Cc, Density (kg/m³). Sensible defaults are pre-filled where possible so you can start with a single change.

Can I embed the Concrete Formwork Pressure Calculator on my own website?

Yes — copy the iframe snippet at the bottom of this page, or use the Embed Generator to customise the size. The embedded version stays in sync with the live calculator on Calcurly.com.