Prism Volume Calculator
Volume and surface area for rectangular and triangular prisms.
Enter your values
Choose one of: Rectangle, Triangle, Trapezoid.
Enter the width / base in units.
Enter the height of the cross-section in units.
Enter the second parallel side (trapezoid only) in units.
Enter the prism length in units.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Volume
- 120 cubic units
- Cross-section area
- 12 sq units
- If units are feet
- 4.4444 cubic yards
- If units are inches
- 0.519 US gallons
- If units are cm
- 0.12 litres
- Prism length
- 10
Quick answer
Every prism's volume is the cross-section area multiplied by its length: V = A × L, no matter the shape of the end face.
V = cross-section area × length
At a glance
| What it does | Volume and surface area for rectangular and triangular prisms. |
|---|---|
| Category | Math |
| Inputs needed | Cross-section, Width / base, Height of the cross-section, Second parallel side (trapezoid only), Prism length |
| Main output | Volume |
| Formula | V = cross-section area × length |
| Cost | Free — no sign-up, no download |
How to use the Prism Volume Calculator
- 1Choose the shape of the end face.
- 2Enter its dimensions, then the length of the prism.
- 3Read the volume plus the handy unit conversions underneath.
Inputs explained
- Cross-section
- Choose one of: Rectangle, Triangle, Trapezoid.
- Width / base(units)
- Enter the width / base in units.
- Height of the cross-section(units)
- Enter the height of the cross-section in units.
- Second parallel side (trapezoid only)(units)
- Enter the second parallel side (trapezoid only) in units.
- Prism length(units)
- Enter the prism length in units.
Worked example
Using the values the calculator loads with:
Inputs
- Cross-sectionRectangle
- Width / base4 units
- Height of the cross-section3 units
- Second parallel side (trapezoid only)6 units
- Prism length10 units
Results
- Volume120 cubic units
- Cross-section area12 sq units
- If units are feet4.4444 cubic yards
- If units are inches0.519 US gallons
- If units are cm0.12 litres
- Prism length10
Frequently asked questions
Does the prism have to be upright?
No. As long as the cross-section is constant along the length, the formula holds however it leans.
What about a cylinder?
A cylinder is a prism with a circular cross-section — use πr² as the area.
What do I need to enter into the Prism Volume Calculator?
Just 5 values: cross-section, width / base, height of the cross-section, second parallel side (trapezoid only), prism length. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Prism Volume Calculator work out the answer?
Every prism's volume is the cross-section area multiplied by its length: V = A × L, no matter the shape of the end face. It applies the formula V = cross-section area × length and shows the working so you can check each step by hand.
Is the Prism Volume Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.