Online Prism Calculator

Prism Volume Calculator

Compute the exact internal 3D cubic capacity and fluid volume across any right prism shape. Includes automated capacity conversions into Liters, Milliliters, Gallons, and cubic measurements.

Base Geometry Selection

Select Prism Solid Type

Step-by-Step Volume Derivation

3D Volumetric Capacity ModelLiquid Level 70%
Primary Volume (V = B × H)
--
cm³
Base Area Component (B)
--
cm²
Equivalent Liquid & Space Capacities
Liters:-- L
Milliliters:-- mL
US Gallons:-- gal
Cubic Feet:-- ft³

Universal Volume Formulas for Prisms

The volume of any right or oblique prism depends solely on the 2D cross-sectional area of the base polygon (B) and the perpendicular height (H). Per Bonaventura Cavalieri’s principle (1635), two prisms having equal heights and equal base areas across all parallel slices share identical internal volume regardless of tilt or curvature.

Rectangular & Cube
V=l⋅w⋅h∣V=a3V = l \cdot w \cdot h \quad | \quad V = a^3

Multiply the base rectangle dimensions by height. In a cube, all dimensions equal a, yielding a³.

Triangular Prism
V=(12bhb)HV = \left(\frac{1}{2} b h_b\right) H

Half of the triangle base edge times triangle height produces Base Area B, then scaled by prism length H.

Regular Hexagonal
V=(332a2)HV = \left(\frac{3\sqrt{3}}{2} a^2\right) H

The regular hexagon base comprises six equilateral triangles, generating 2.598076 · a² multiplied by height H.