Math
Rectangular Prism Surface Area Calculator
Use this rectangular prism surface area calculator when you need the outside area of a box-shaped solid.
Try an example
Result
Surface area
—
- Surface area
- —
- Front and back pair
- —
- Top and bottom pair
- —
- Volume check
- —
Student quick launch
Grade planning, algebra checks, and formulas students reach for most.
Study path
Use this calculator with
Follow these when you want the formula behind the answer, a short lesson, or nearby tools in the same topic.
What the rectangular prism surface area calculator solves
Use this rectangular prism surface area calculator when you need the outside area of a box-shaped solid.
Formula
How to use it
- Enter the shape dimensions using one consistent unit system.
- Check the formula and supporting measures before copying the answer.
- Use square units for area results and cubic units for volume results.
How to read the answer
Surface area adds the areas of all six rectangular faces. The face-pair breakdown helps you check the formula without losing a side.
Common mistakes and edge cases
- Do not calculate only one face.
- Use square units for surface area.
- Keep volume separate because it measures inside space, not outside covering.
Worked examples
Gift box
Surface area
Surface area = 158 square units
Flat package
Surface area
Surface area = 279 square units
Impossible surface area
Surface area
Error
Frequently asked questions
Why is there a 2 in the formula?+
Each pair of opposite faces has the same area: front/back, top/bottom, and left/right.
Is surface area the same as volume?+
No. Surface area covers the outside in square units; volume fills the inside in cubic units.
About this calculator
- Written by
- mathcheck editorial team
- Last reviewed
- May 15, 2026
Method
- Uses the values entered by the user and stable formulas documented on the page.
Related calculators
Rectangular Prism Volume Calculator
Calculate rectangular prism volume, surface area, and space diagonal from length, width, and height.
Area Calculator
Find the area of 11 shapes — rectangle, square, triangle (base-height, three sides, or SAS), circle, trapezoid, parallelogram, rhombus, ellipse, regular polygon, sector, and kite — with the formula, substitution, square-unit labels, and a diagram.
Volume Calculator
Find the volume of 11 solids — cube, box, cylinder, cone, sphere, hemisphere, pyramid, triangular prism, ellipsoid, capsule, and frustum — with exact π forms, cubic-unit labels, surface area, and liters/gallons capacity.
Circle Segment Area Calculator
Calculate circular segment area from radius and central angle, with sector, triangle, and arc-length checks.
Ellipse Area Calculator
Calculate ellipse area from semi-major and semi-minor axes with the pi a b formula and equal-area circle check.
Regular Polygon Area Calculator
Calculate regular polygon area from side length and number of sides.
Last updated: May 15, 2026