MEP calculations
that reference the standard
Replace spreadsheets with traceable calculations. Cable sizing, duct sizing, HVAC loads, pipe sizing, drainage, refrigeration, every result linked to BS 7671, CIBSE, ASHRAE or BS EN standards.
Standards traced
The problem MEPCalc solves
What working from spreadsheets actually looks like.
Spreadsheet chaos
Three filenames, three different cable sizes. Only one ends up on the drawing, and you can't always tell which is right.
Source uncertainty
A value lands in your spec from somewhere. Which edition of the standard? Whose template? Three years on, nobody knows.
Audit trail is blank
Auditors ask: what standard, what assumption, what date. Spreadsheets don't record any of it. You can't prove your work.
MEPCalc replaces the spreadsheet.
Every calculation traceable to the standard. Every result auditable. Every assumption visible.
Join the waitlist50+ calculators across MEP disciplines
Every calculation referenced to the engineering standard
Electrical
- Cable sizing, voltage drop BS 7671:2018+A3:2024
- Fault levels + protective devices BS 7671 App 14
- Load schedules + motor starters + UPS IET OSG / BS 7671 / IEC 62040-3
- EV charging BS 7671 §722
- Generators ISO 8528-1
- Emergency lighting BS 5266 / BS EN 1838
HVAC
- Space load CIBSE Guide A / ASHRAE
- Fabric heat loss + solar gains BS EN 12831-1 / CIBSE Guide A
- AHU + heat recovery CIBSE B3
- Heat source CIBSE B1 + AM16
- Underfloor heating BS EN 1264-2:2021
- Expansion vessel BS EN 12828 Annex D
Ventilation
- Ventilation design CIBSE B2 / Part F / BB101 / HTM 03-01
- Natural ventilation BS EN 16798-7 / ASHRAE 62.1
- Whole-dwelling Part F / ASHRAE 62.2
- Ductwork + insulation CIBSE B2 / BS 5422:2023
- Standalone fans + acoustic CIBSE B4
Plumbing & Drainage
- Pipe sizing CIBSE Guide G
- Hot/cold water + DHW storage CIBSE Guide G / BS 8558
- Drainage BS EN 12056-2 + Part H
- Legionella RA HSG 274
Refrigeration
- Cold-store loads IOR CoP 2020 / ASHRAE
- Pipe sizing BS EN 12735-1 / ASHRAE
- Datacentre cooling ASHRAE TC 9.9 5th ed
- Refrigerant data BS EN 378-1
Acoustic + Renewables
- Duct noise CIBSE B4 + BS 848
- Solar thermal SAP 10.3 App H + MCS MIS-3001
- Solar PV SAP 10.3 App M / MCS MIS-3002
How it works
Select
Browse 50+ calculators across 6 disciplines. Search by name or by the standard you need to reference.
Enter
Every input field carries the source standard. Hover any field to see the table or clause it pulls from.
Export
Get an auditable PDF with formula breakdown, all assumptions, and a citation for every value used.
Designed for engineers who care about standards
No shortcuts. No approximations. Just traceable, auditable MEP engineering.
Join the waitlistTransparent pricing. No surprises.
Start free for 7 days. No credit card required. Cancel anytime.
Single Module
Pick one calc module
or £299/yr (save £61)
Includes
- Access to one calculator module
- Full standard references
- PDF export
Single Discipline
Most popularAll modules in one discipline (HVAC, Electrical, or Plumbing)
or £549/yr (save £171)
Includes
- All calculators in your chosen discipline
- Standards references per discipline (BS 7671, CIBSE Guide A + B, BS EN, ISO, Approved Docs F + L)
- Unlimited PDF reports
Full Suite
All 48 modules across HVAC, Electrical, and Plumbing
or £1299/yr (save £501)
Includes
- Every calculator across all sellable disciplines
- Full standards coverage, including BS 7671, CIBSE Guide A + B, BS EN 12831-1 / 16798-1, ISO 8528, BS 5422:2023, Approved Docs F + L, BS 5266 / BS EN 1838 / BS EN 50172, HSG 274
- Unlimited PDF reports
All plans include a 7-day free trial, per seat, no credit card required