Wire it right the first time.
Plain-language, code-aware how-tos for homeowners and DIYers — from swapping a receptacle to sizing a circuit — plus live calculators so you check the numbers before you touch a wire.
Educational reference only — not a substitute for your local Authority Having Jurisdiction (ESA in Ontario), a permit, or a licensed electrician where required.
Baseline copper ampacity, 60°C column, single 3-conductor NMD90 cable — no bundling, ambient-temperature, or run-length derating applied. Always verify against the current CEC and your local ESA amendments before sizing a real circuit.
Derating, permits, and inspections are exactly where DIY gets risky — Durham Region & the GTA.
Hire an Electrician →
Step-by-step guides
Each guide covers tools, code requirements, and the exact steps — flagged by skill level.
See all guides →Plugs & Receptacles
Confirm the circuit is dead, match the device rating, and land the wires correctly — the most common first DIY job.
IntermediateLighting, Switches & Fixtures
Single-pole, 3-way, and 4-way switching, dimmers, smart-switch neutrals, fixture swaps, and ceiling fans.
BeginnerPanels & Breakers
Warning signs you've outgrown your panel, how to size a new service, and whether fuse panels are safe.
BeginnerKitchen & Bathroom Rules
Countertop circuit counts and spacing, split receptacles, GFCI radius, and switch clearance from a tub.
BeginnerSmoke & CO Alarms
Placement requirements, interconnection rules, and why alarms tie into a lighting circuit.
BeginnerTroubleshooting Common Problems
Flickering lights, tripping breakers, warm outlets, burning smells, and sudden bill spikes.
Reference GuideAFCI & GFCI: What Needs What
A panel diagram mapping which circuits need AFCI, GFCI, both, or typically neither.
Permit requiredDetached Garage, Shed & Gazebo Power
Direct burial depths by project, disconnects, bonding — and why pool equipment is a no-DIY zone.
The Riley Group Electrical
Licensed electricians serving Durham Region and the surrounding GTA. This site is the free how-to arm of our business — when a job goes past DIY, hire us directly.
Working calculators
Live tools that update as you type — 47 live tools and counting.
See all calculators →Ohm's Law Solver
Enter any two of V, I, R — solves the rest plus wattage in real time.
Wire Gauge & Ampacity (NMD90)
Match conductor size to breaker rating — copper NMD90, CEC Table 2.
● LiveBreaker Size
Watts or amps in — minimum standard breaker out, with the 125% continuous-load rule built in.
● LiveVoltage Drop
Check run length against conductor size — flags anything over the 3%/5% guideline.
Panel Load Calculation
Estimate total demand load for a dwelling per CEC Section 8.
More calculators
Tackle your specific project - pick the right tool.
See all 44 calculators →Panel Load Calculator
Estimate total demand per CEC Section 8.
Panel Upgrade Estimator
Know if your panel needs an upgrade before you call.
EV Charger Load
Check if your panel can handle a Level 2 charger.
Outlet Load Calculator
Check circuit load before adding outlets.
Pot Light Spacing
Calculate how many pot lights per room.
Overloaded Circuit Check
Diagnose if a circuit is running too hot.
Generator Size Calculator
Right-size a backup generator for your home.
Direct Burial Calculator
Burial depth, cable type, and conduit rules.
Electrical Cost Calculator
Estimate what a device or circuit costs to run.