Geometry & Shapes
Prism Calculator
Prism: it uses the rectangular-prism formulas — volume = l·w·h and surface area = 2(lw + lh + wh). Worked through below with real figures, and the calculator repeats the working on your own inputs — free, on-device, instant.
Use Prism Calculator to find the volume and surface area of the solid: give it your length, width and height, press Calculate, and read off the volume and surface area — all worked out on your device.
About this calculator
It uses the rectangular-prism formulas — volume = l·w·h and surface area = 2(lw + lh + wh). It matters whenever a shape has to be measured, cut, covered or compared and the geometry has to be right first. Worked below as A triangular prism with triangle area 12 and length 10: volume = 12 × 10 = 120 . — and the calculator on this page repeats exactly that working for your inputs, instantly, and offline after load.
How to use
- Enter the length.
- Enter the width.
- Enter the height of the box.
- Press Calculate to read the volume and surface area.
Why use Prism Calculator
Fast
Calculations run in your browser. No round trip to a server.
Private
Your inputs never leave your device. Nothing is uploaded.
Free
No signup, no paywall, no ads-in-results, no watermarks.
Accurate
Uses standard formulas for quick educational estimates; check critical results before relying on them.
Mobile-ready
Optimised for phones, tablets, and desktops alike.
Transparent
Honest disclaimers wherever browser limits or regional rules apply.
Common uses
Use it for volume and capacity checks
Use it for packaging and box design
Use it for 3D modelling and CAD prep
Use it when planning storage capacity
Use it when estimating surface area to paint or coat
Use it for material-volume estimates
Technical notes
Prism Calculator uses the rectangular-prism formulas — volume = l·w·h and surface area = 2(lw + lh + wh).
Results assume exact, idealised shapes; real-world measurement error is not included.
Results are rounded for display; the underlying calculation keeps full precision.
FAQ
Which prism does this calculate?
It calculates a rectangular prism (a box) from its length, width, and height.
How is the prism's surface area found?
It adds the areas of all six rectangular faces: 2(lw + lh + wh).
What is the space diagonal?
It is the longest line through the box, the square root of length squared plus width squared plus height squared.
Does the Prism Calculator send my data to a server?
No. The Prism Calculator runs entirely in your browser, so nothing you enter is uploaded, stored, or shared.
Worked example
A triangular prism with triangle area 12 and length 10: volume = 12 × 10 = 120.