Triangular Prism Surface Area Calculator

Where b is the base of the triangle, h is the height of the triangle, and the prism height is H.

More precisely:

Where a, b, c are the sides of the triangular base and H is the prism height.

Calculate the surface area of a triangular prism with base triangle sides 3 cm, 4 cm, 5 cm, triangle height 2.4 cm, and prism height 10 cm:

Base area:

Lateral surface area:

Total surface area:

Result: 127.2 cm²

1. Enter the three sides of the triangular base
2. Enter the height of the triangular base
3. Enter the height of the prism
4. Click "Calculate" to see the surface area

• Volume: $\\\\frac{1}{2} \\\\times \\\\text{base} \\\\times \\\\text{height} \\\\times \\\\text{prism height}$
• Base area (Heron's formula): $\\\\sqrt{s(s-a)(s-b)(s-c)}$ where $s = \\\\frac{a+b+c}{2}$
• Lateral surface area: Perimeter of base × prism height

• Roof truss calculations
• Tent and shelter design
• Packaging for triangular products
• Architecture and engineering

What if the base is equilateral? All sides equal: $\\\\text{surface area} = \\\\frac{\\\\sqrt{3}}{2}s^2 + 3sH$.

How is this different from volume? Surface area is the total area of all 5 faces (2D); volume is the space inside (3D).

Can I calculate from volume? No, you need all dimensions separately.

What about an open triangular prism? Subtract the area of the missing face(s).