Space Diagonal of a Cuboid Calculator
🧊 Volume & surface area (3D). Use the Space diagonal of a cuboid formula to find diagonal, length, width, height: pick the value you want, type the others, and the answer updates as you go.
Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.
What each letter means
| Quantity | Unit |
|---|---|
| Diagonal | cm |
| Length | cm |
| Width | cm |
| Height | cm |
Worked example
Find the diagonal when Length = 5 cm, Width = 4 cm, Height = 3 cm.
Using d = √(l² + w² + h²): Diagonal = 7.0711 cm.
Frequently asked questions
What is the formula for Space diagonal of a cuboid?
d = √(l² + w² + h²).
What do the letters stand for, and what units are used?
Diagonal in cm, Length in cm, Width in cm, Height in cm.
How do you calculate diagonal?
Put the values into d = √(l² + w² + h²). For example, with Length = 5 cm, Width = 4 cm, Height = 3 cm, diagonal = 7.0711 cm.
Can I solve for a different value?
Yes. In the calculator above, pick the circle next to any value (diagonal, length, width, height) and fill in the others: it rearranges the formula for you.
