Systems — United States
Start with measured geometry and the supplier’s actual purchasing units. Round order quantities only after applying the specified waste allowance, then add material, labor, delivery and other costs without double counting. This directory groups systems tools for United States; individual pages state their supported inputs and limitations.
Start with these tools
Wire Voltage Drop Screening Calculator — United States
Screen the resistive voltage drop of a DC or idealized single-phase two-conductor circuit using explicit material resistivity. USD planning view; stated limitations apply.
Electrical Panel Load Screening Calculator — United States
Check a specified single-phase demand scenario without applying an invented code demand schedule. USD planning view; stated limitations apply.
Pipe Flow and Diameter Screening Calculator — United States
Translate an explicit design flow and velocity into a geometric bore diameter. USD planning view; stated limitations apply.
Duct Area and Diameter Screening Calculator — United States
Calculate an equal-area duct geometry for a specified airflow and velocity, not a fan-pressure design. USD planning view; stated limitations apply.
Water Heater Storage and Recovery Calculator — United States
Relate a specified mixed-water draw to ideal storage and recovery power using an explicit temperature balance. USD planning view; stated limitations apply.
Open a tool, check the displayed formula and enter values from the same period and measurement system. Currency defaults to USD. Where a form offers metric and imperial units, changing the selector converts the entered measurements rather than relabeling the same number. Dated reference components are shown with their sources; unverified rules and prices are not silently treated as current local facts. Save distinct assumptions as separate scenarios and compare their inputs before their outputs. Shared links can disclose the input values they contain. The implemented expansion is still subject to its published scope-acceptance checks, including missing regional datasets and production-browser verification.
systems
Wire Voltage Drop Screening Calculator — United States
Screen the resistive voltage drop of a DC or idealized single-phase two-conductor circuit using explicit material resistivity. USD planning view; stated limitations apply.
Electrical Panel Load Screening Calculator — United States
Check a specified single-phase demand scenario without applying an invented code demand schedule. USD planning view; stated limitations apply.
Pipe Flow and Diameter Screening Calculator — United States
Translate an explicit design flow and velocity into a geometric bore diameter. USD planning view; stated limitations apply.
Duct Area and Diameter Screening Calculator — United States
Calculate an equal-area duct geometry for a specified airflow and velocity, not a fan-pressure design. USD planning view; stated limitations apply.
Water Heater Storage and Recovery Calculator — United States
Relate a specified mixed-water draw to ideal storage and recovery power using an explicit temperature balance. USD planning view; stated limitations apply.
Frequently asked questions
Does this directory imply full local-rule coverage?
No. Each calculator states its scope. An implemented mathematical worksheet is not the same as a fully researched statutory calculator.
Where do the amounts come from?
Either your inputs or an explicitly named and dated reference component. Illustrative defaults are not supplier quotes or market averages.
Can I compare assumptions?
Use the individual calculator’s scenario controls. Read its formula, period, units and limitations before comparing results.