Reproduce circular area and volumetric flow from a source-labelled actual inside diameter and documented average velocity, then compare an independent flow record without selecting demand, capacity or compliance.
A quick decision brief for this specific tool
One de-identified reviewed flow segment; named actual inside-diameter, average-velocity and independent comparison-flow records; one paired inch/ft-per-second/GPM or millimetre/metre-per-second/litre-per-second unit system; and positive documented actual ID and velocity plus a finite comparison flow
Source-preserving internal area, raw volumetric flow, reproduced flow, independent comparison flow and signed reproduced-minus-comparison difference
Convert the entered actual inside diameter within its paired unit system, calculate circular area and Q = A x documented average velocity, then compare only with the entered independent flow record; do not infer demand, pressure loss, available capacity, allowable velocity, pipe size or compliance
Choose your path
Reproduce volumetric flow from one source-labelled actual inside diameter and documented average velocity, then compare an independent flow record without deriving demand, pressure loss, capacity or compliance.
Check Q = A x V against an actual product inside diameter without a pressure shortcut or nominal-size assumption.
Name the design, ID, velocity and comparison-flow records; choose a paired unit system; inspect area, flow and signed difference.
Can trace the continuity calculation while demand, friction, pipe selection and approval remain in the complete design.
Reconcile a meter record with documented average velocity and internal geometry while preserving operating context.
Select measurement basis, identify calibration/location/time records, enter the actual ID and average velocity, then compare the independent flow.
Sees an arithmetic difference without an available-flow, capacity or pass/fail verdict.
Understand circular area and Q = A x V without confusing GPM, L/s, nominal diameter or a selected velocity limit.
Run separate US and metric education records and review each explicit conversion and exclusion.
Can reproduce both unit paths and list the demand, pressure, friction, material and authority checks the tool omits.
Outputs and checklists are planning aids. Review the linked current authorities and the records, terms, instructions, and requirements that apply to your exact situation before a consequential decision.
Tools you might need next
Audit source-labelled flow, velocity, circular area and theoretical inside-diameter arithmetic against one already documented candidate ID—without selecting nominal pipe, material or compliance.
Audit a source-labelled pressure-component ledger against an independent endpoint record—without inventing friction/elevation losses, clamping pressure or selecting pipe, pump or regulator.
Estimate wait time for hot water at fixture from water heater. Free online plumbing calculator with instant, accurate results.
Copy actual internal flow diameter from the exact product, drawing or measurement record. Nominal or trade size is not substituted because material and wall class change internal area.
A = π × actual ID² ÷ 4Use inches with ft/s and GPM, or millimetres with m/s and L/s. The velocity is copied from its responsible calculation or measurement; the record does not choose an allowable velocity.
Q = A × documented average velocityThe comparison records arithmetic agreement only. It does not establish demand, available supply, meter validity, sufficient capacity, pressure performance, pipe selection or approval.
Difference = reproduced flow − documented comparison flowUpdated: August 2026
A designer copies actual product ID and a velocity already established by the responsible calculation, then compares Q = A × V with the design flow record while retaining all pressure-loss work externally.
A reviewer identifies measurement location, time and calibration context, reproduces flow from documented average velocity and actual ID, and treats the signed mismatch as an investigation prompt rather than a verdict.
An apprentice enters millimetres, metres per second and litres per second as one paired record, then reviews the conversion without pressure, roughness or nominal-pipe assumptions.
Preserve the provenance of one actual inside diameter, one documented average velocity and one independent comparison flow. The record calculates only circular area, Q = A × V and a signed difference in a complete US or metric unit system; it does not convert pressure into available flow or choose a design criterion.