ConcreteCalc
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Concrete Triangle Calculator

To calculate concrete volume for a triangular pour: calculate the triangular surface area (½ × Base × Height, or via Heron's Formula for three unequal sides), multiply by the slab thickness, and divide by 27 for cubic yards. Add 10% to account for formwork spread and subgrade unevenness.

Interactive Concrete Triangle Calculator

ENGINEERING SCHEMATIC
Triangular Concrete Pour Geometry
Volume (V) = Area × Depth 1 Cubic Yard = 27 Cubic Feet
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Pro Contractor Recommendation: Calculate base times height divided by 2, then multiply by thickness. Ideal for angled patio corners, driveway aprons, and property line wedges.
Calculation Method
Base & Height Dimensions
Thickness & Waste
Triangular Pour Concrete Volume
0.54 Cubic Yards (yd³)

Includes 10% waste (Net: 0.49 yd³)

Surface Area
40.0 sq ft
3.72 m²
Perimeter / Formwork
30.8 linear ft
Required edge forms
Cubic Feet (Gross)
14.7 cu ft
0.42 m³
80 lb Pre-Mix Bags
25 bags
Or 33 x 60lb bags

When to Use a Triangular Concrete Calculator

Triangular concrete pours are common in residential and commercial landscape engineering:

  • Patio & Walkway Corner Cutoffs: Chamfered 45-degree or angled transitions between perpendicular walkways.
  • Driveway Apron Flares: Triangular transitions connecting the street curb radius to the main driveway slab.
  • Wedge-Shaped Steps & Landings: Curved or angled entrance porches.
  • Triangular Equipment Pads: Corner heat pump, generator, or pool equipment foundations.

Triangular Area Calculation Methods

1. Base & Height (Right or Perpendicular Triangle):

Surface Area = 0.5 × Base × Height

2. Three Unequal Sides (Heron's Formula):

s = (Side A + Side B + Side C) / 2

Surface Area = √[s × (s - Side A) × (s - Side B) × (s - Side C)]

Volume = Surface Area × Thickness

Formwork & Perimeter Form Bracing

Acute corner angles in triangular slabs require reinforced form staking. When pouring concrete into acute wedge corners, concrete aggregate can jam and create honeycombing unless carefully vibrated or hand-tamped into the points of the forms.