MEP calculations
that reference the standard
Replace spreadsheets with traceable calculations. Cable sizing, duct sizing, HVAC loads, pipe sizing, drainage — every result linked to BS 7671:2018+A3:2024, CIBSE, or AD F 2021.
The problem MEPCalc solves
Spreadsheet chaos
Excel files emailed around, versions colliding, no audit trail. Which version is correct?
Standards uncertainty
Where did this formula come from? Which edition of BS 7671? You're guessing.
Compliance risk
No traceability. Auditors want to know: what standard, what assumption, what date. You can't prove it.
MEPCalc replaces the spreadsheet.
Every calculation traceable to the standard. Every result auditable. Every assumption visible.
40+ calculators across MEP disciplines
Every calculation referenced to the engineering standard
Electrical
- Cable sizing, voltage drop, fault levels, load schedules, generators, protective devices, EV charging, PV, motor starters, UPS, emergency lighting + more
HVAC & Mechanical
- Duct sizing
- HVAC loads
- Ventilation
Plumbing & Drainage
- Pipe sizing
- Hot/cold water
- Drainage design
- Legionella control
Renewables
- Solar thermal
How it works
Select
Choose the calculator for your task. Browse by discipline or search for the standard you need.
Enter
Input your parameters and assumptions. Every field is labelled with the relevant standard reference.
Export
Get traceable results with formula breakdown, standard references, and audit trail.
Designed for engineers who care about standards
No shortcuts. No approximations. Just traceable, auditable MEP engineering.
Every calculation references the standard
MEPCalc doesn't give you a black-box number. It shows you where every value comes from.
BS 7671:2018+A3:2024
Electrical Safety
- Cable sizing
- Fault levels
- Load schedules
CIBSE Guide A
HVAC Load Calculations
- Cooling loads
- Heating loads
- Solar gains
CIBSE Guide C
HVAC & Energy
- Duct sizing
- Plant sizing
- System design
BS 5422:2023
Pipe & Duct Insulation
- Thermal insulation
- Condensation risk
- Heat loss prevention
AD F 2021
Ventilation / Building Regs
- Ventilation rates
- Air quality
- Building Regs compliance
CIBSE AM10
Acoustic Design
- Sound levels
- Duct noise
- Attenuation
No approximations. No shortcuts.
Every formula is auditable. Every assumption is visible. Every calculation is traceable.
Transparent pricing. No surprises.
Start free for 14 days. No credit card required. Cancel anytime.
Single Module
Pick one calc module
or £299/yr (save £61)
- Access to one calculator module
- Full standard references
- PDF export
Single Discipline
All modules in HVAC, Electrical, OR Plumbing
or £549/yr (save £171)
- All calculators in your chosen discipline
- Full standard references (BS 7671, CIBSE, AD F)
- Calculation history & audit trail
Full Suite
All 48 modules across all 3 disciplines
or £1299/yr (save £501)
- Every calculator across HVAC, Electrical & Plumbing
- All standards (BS 7671, CIBSE Guide A/C, BS 5422, AD F, CIBSE AM10)
- Project management & collaboration
- Calculation history & audit trail
All plans include a 14-day free trial · per seat · no credit card required
Stop emailing spreadsheets.
Start traceable calculations.
7 days free. No credit card. Cancel anytime. MEPCalc is purpose-built for UK MEP engineers.
Request early access