ExploreCalculators
Calculators
Size systems in seconds with UK MEP calculators grounded in British Standards and Approved Documents.
What it is
Size it. Check it. Move on.
BuildFlo Calculators are the deterministic sizing layer for UK building services design. Run pipe, duct, U-value, lux, voltage drop, MVHR, and dozens more tools - with results you can keep on the project instead of buried in disposable spreadsheets.
Product
What it does
- Run UK MEP sizing tools
Pipe and duct sizing, U-values, lux levels, voltage drop, MVHR, heat loads, and more - framed for UK practice units and standards.
- Keep results with the job
Save calculation outputs into the project workspace so the next engineer can see what was run - not hunt for someone's desktop Excel file.
- Try before you sign in
Public calculator pages let visitors explore core tools. Full project saving and the wider set live inside the BuildFlo account.
Demo
Pick a calculator.
Jump into featured UK MEP tools, or browse the full public catalogue.
- Pipe sizingSize from flow or loading units - equivalent sizes across copper, steel, and plastic
- Duct sizingCheck duct velocity, Pa/m, equivalent Ø and sound from flow and dimensions
- U-valueWall, roof, floor, window or door U-value with Part L dwelling / commercial check
- Lux levelsLumen-method sizing, maintained lux checks, BS 5266 emergency and LPD
- Voltage dropMinimum CSA for voltage-drop limits, or check a proposed cable
- MVHR sizingPart F continuous MVHR duty, wet-room boost, heat recovery winter supply, and indicative ducts
Benefits
Why practices use it
Built for how UK MEP consultancies actually win and deliver work.
Less spreadsheet archaeology
Stop digging for the last good pipe-sizing sheet. Use a consistent toolset the whole practice can open.
Built for UK regs framing
Guidance and defaults lean on Approved Documents and British Standards rather than generic US or metric-only internet calculators.
Works with Agent and drawings
Calculators sit beside standards Q&A and Drawing QA - so sizing, checking, and citing happen in one workflow.
Fast enough for design time
Get a first-pass size, sanity-check it, and move on - without rebuilding formulas every Friday afternoon.
FAQ
Questions, answered.
- Are calculators free to try?
- Yes. Core public calculators are available on the marketing site. Creating an account unlocks the full set, project saving, and the rest of the BuildFlo workspace.
- Do calculator results replace engineer sign-off?
- No. They accelerate sizing and checking. Always verify critical results against project assumptions, manufacturer data, and the relevant standard before issue.
- How many calculators are there?
- BuildFlo ships dozens of UK MEP tools across mechanical and electrical design - with more added as the product expands. Browse the public catalogue for the current list.
Run the next calc in BuildFlo.
Free in early access. Create an account, or open Calculators if you already have access.