Column Formwork Calculator

Inputs

Results update as you type.

Column

Column shape

Column width

Column depth

Pour heightBase to top of the pour.

Number of columns

Concrete placement

Placement rateVertical rise of concrete in the form per hour.

m/h

Concrete temperatureAt placement. Colder concrete sets slower and pushes harder.

°C

Cement / admixture

Concrete density

kg/m³

Placement methodSelf-consolidating concrete, slump over 175 mm (7 in), pumping from the base or revibration deeper than 1.2 m (4 ft) all require full liquid head.

Formwork

Facing sheet size

Clamp / yoke spacingUse the spacing from your formwork supplier or design.

Wastage

Diagram updates as you type.

Results

Check the working before you order.

Facing sheets required

3sheets, 10% waste incl.

Contact area	7.0 m²
Clamp / yoke sets	9 sets
Concrete volume	0.84 m³

Peak lateral pressure on formwork

82.4 kPa

100% of full hydrostatic pressure at this height: full liquid head w·h governs.

Price This optional: add your own prices

Result to priceMaterial price per unitLabour rate per unitCurrency

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Working

Cw = 1.000 (from density); Cc = 1.0; R = 19.69 ft/h; T = 68 °F
ACI 347: p = Cw·Cc·(150 + 9000R/T) = 131.9 kPa
Limits: minimum 600·Cw psf; maximum w·h = 82.4 kPa
Design pressure = 82.4 kPa, reached 3.50 m below the top of the pour
Contact area = 2 × (W + D) × H × n = 2 × (0.40 + 0.60) × 3.50 × 1 = 7.0 m²
Clamp sets = (⌈H ÷ 450⌉ + 1) × 1 = 9
Clamps at the base carry the highest pressure (82.4 kPa); many suppliers close up clamp spacing in the bottom third.

Results are estimates for planning and material ordering only. They are not a substitute for structural design or approval by a qualified engineer. Read the full disclaimer.

Column Formwork Calculator byMy Construction Calculator: free construction calculators with the working shown.