Compare calculators

Both calculators run independently — change the inputs on either side to compare results.

Flexible Pavement Thickness Calculator

Compute the required flexible pavement structural number using the AASHTO 1993 empirical design method. Used by pavement engineers to size asphalt road sections for a given traffic load, subgrade strength, and reliability level.

Design ESALs (applications)

Reliability Level

Subgrade CBR (%)

Serviceability Loss

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Civil

Pipe Flow Calculator (Hazen-Williams)

Determine water flow rate and velocity in pressurized pipes using the Hazen-Williams empirical equation. Ideal for civil engineers sizing water mains, irrigation lines, or fire-suppression systems.

Pipe Diameter (mm)

Pipe Length (m)

Head Loss (m)

Hazen-Williams Coefficient

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Key differences

	Flexible Pavement Thickness Calculator	Pipe Flow Calculator (Hazen-Williams)
Category	Civil	Civil
Inputs required	4	4
Result	Structural Number Required (SN)	Flow Rate (L/s)
What it does	Compute the required flexible pavement structural number using the AASHTO 1993 empirical design method. Used by pavement engineers to size asphalt road sections for a given traffic load, subgrade strength, and reliability level.	Determine water flow rate and velocity in pressurized pipes using the Hazen-Williams empirical equation. Ideal for civil engineers sizing water mains, irrigation lines, or fire-suppression systems.