Calculators

Rectangular Tube Calculator

Calculate hollow rectangular tube material volume and inner, outer, and total surface areas from outer and inner dimensions and length.

Model a straight rectangular tube open at both ends with a centered rectangular opening. Enter outer width and depth, inner width and depth, and tube length in the same unit, from 1e-50 to 1e50. Each inner dimension must be smaller than its outer dimension. Total surface area includes inner walls, outer walls, and both end rims. Rounded corners are not included. Calculations stay in your browser.

Measure a hollow rectangular prism.

For a straight rectangular tube with sharp corners, outer dimensions W and D, inner dimensions w and d, and length L, material cross-section B = WD − wd. Material volume = BL. Outer lateral area = 2(W + D)L; inner lateral area = 2(w + d)L. Total surface area = 2(W + D)L + 2(w + d)L + 2B, including both open end rims. For outer dimensions 8 by 6, inner dimensions 6 by 4, and length 10, B = 24 square units, volume = 240 cubic units, and total surface area = 528 square units. The opening is centered; wall thicknesses are (W − w)/2 and (D − d)/2 and need not be equal. This model ignores corner radii and does not include end caps. Enter positive dimensions from 1e-50 to 1e50 with each inner dimension strictly below its corresponding outer dimension. Scientific notation is accepted. Results use browser floating-point arithmetic rounded to 12 significant digits. Inputs stay in your browser.

Frequently Asked Questions

Everything you need to know about this tool, how it works, and privacy.

Does this calculate material volume or empty space?

It calculates material volume: subtract the inner rectangular cross-section from the outer one, then multiply by length.

Which surfaces are included?

Total surface area includes all four outer walls, all four inner walls, and the two rectangular end rims. The tube is open at both ends; end caps and rounded corners are excluded.

What is an example?

Outer width 8, outer depth 6, inner width 6, inner depth 4, and length 10 give material volume 240 cubic units and total surface area 528 square units.

Can wall thickness differ between directions?

Yes. A centered opening has width-direction thickness (W − w)/2 and depth-direction thickness (D − d)/2. Inner dimensions must be positive and strictly smaller than the corresponding outer dimensions.

Are measurements uploaded?

No. Calculations and copying run locally in your browser.