Electrical Calculators

Free BS 7671 compliant calculators for UK electricians

Cable Size Calculator

Calculate the correct cable size for any circuit

Voltage Drop Calculator

Check voltage drop against BS 7671 limits

Max Zs Calculator

Maximum earth fault loop impedance values

Fault Current Calculator

Calculate prospective fault current (PFC)

Diversity Calculator

Maximum demand after diversity

Ring Final Calculator

Ring circuit continuity and Zs verification

Earthing & Bonding

CPC, main earthing and bonding conductor sizes

Conduit Fill Calculator

Check conduit and trunking cable capacity

Three Phase Balance

Balance loads across three phases

EV Charger Calculator

Cable sizing and circuit requirements for EV chargers

Motor Circuit Calculator

Cable sizing and protection for motor circuits

Lighting Circuit Calculator

Cable sizing for lighting with inrush current

Coming Soon

Solar PV Calculator

LED Savings Calculator

Generator Sizing

UPS Sizing