Electrical
Electrical Work Calculator
Build a room-by-room electrical schedule, from appliance loads to cable runs back to your distribution board (DB).
Results update as you type. Nothing to sign up for.
Measurements
Country changes guidance and sizing availability. Reference estimates are not local compliance certificates.
Confirm the actual line-to-neutral supply. Automatic size candidates cover 200–250 V only.
Electrical plan
Rooms and appliances
Add every load, including portable heaters and future appliances. All route lengths are in metres, measured along the cable path. Preset powers are examples to replace with nameplate inputs.
References and sizing scope
Cable candidates use conservative IEC reference capacities for copper PVC multicore cable. Country selection does not certify compliance. No automatic main breaker, ring, split-phase, three-phase, buried or EV design is supplied.
| mm² | A2 | B2 | C |
|---|---|---|---|
| 1.5 | 13 | 15 | 17.5 |
| 2.5 | 17.5 | 20 | 24 |
| 4 | 23 | 27 | 32 |
| 6 | 29 | 34 | 41 |
| 10 | 39 | 46 | 57 |
| 16 | 52 | 62 | 76 |
You need approximately
39.6m
of estimated cable route, including ordering allowance
Connected load
0.02kW
Proposed circuits
2
Twin socket positions entered
3
Light fittings entered
2
Planning estimate for electrician review. No installation is approved by this calculator. Fault protection, earth conductor sizing, local rules and manufacturer limits must be verified before buying cable or breakers.
Socket groups use all listed loads simultaneously and split at 20 A. Each group repeats the full room route; confirm the actual grouping and takeoff. Empty sockets are not a load allowance: add future appliances explicitly.
Motors, compressors, LED drivers and electronic appliances need starting-current and protective-device checks. EV charging, outdoor routes and unsupported supplies do not receive automatic sizes.
Cable takeoff by candidate size
- Cable awaiting design
- 39.6 mallowance included; core configuration to be confirmed
Design scope
- Country
- Mauritius — IEC reference estimate
- Protection and DB
- Have an electrician specify RCD/RCBO type, trip curve, fault breaking capacity, earthing, disconnection time and DB ways. Connected load is not the main breaker rating.
Room 1: Bedroom — Lighting
- Appliances / lights
- Lighting
- Electrical input
- 20 W
- Full-load current
- 0.1 A
- DB to furthest point
- 15 mone-way, before switch cable
- Cable takeoff
- 19.8 mincludes switch cable and ordering allowance
- Assessment
- Confirm nameplate loads and routes before showing size candidates.
Room 1: Bedroom — Sockets 1
- Appliances / lights
- No socket appliances entered
- Electrical input
- 0 W
- Full-load current
- 0 A
- DB to furthest point
- 18 mone-way, before switch cable
- Cable takeoff
- 19.8 mincludes switch cable and ordering allowance
- Assessment
- Confirm nameplate loads and routes before showing size candidates.
Room 1: Bedroom — positioning
- Room use
- Bedroom
- Twin positions for listed simultaneous plugs
- 0load-list count only; allow extra positions for furniture and future use
- Placement plan
- Place outlets on both sides of the bed and at the desk or dressing table. Keep them accessible after wardrobes are fitted; plan a vacuum point near the entrance. Include heaters and air conditioning in the load list.
- Socket provision
- Set the count from furniture, appliance positions and local requirements.
Cable reference chart — corrected capacities
- 1.5 mm² copper
- 15 Athermal reference only; see circuit voltage-drop check
- 2.5 mm² copper
- 20 Athermal reference only; see circuit voltage-drop check
- 4 mm² copper
- 27 Athermal reference only; see circuit voltage-drop check
- 6 mm² copper
- 34 Athermal reference only; see circuit voltage-drop check
- 10 mm² copper
- 46 Athermal reference only; see circuit voltage-drop check
- 16 mm² copper
- 62 Athermal reference only; see circuit voltage-drop check
Purchasing follows electrician review
How to measure the actual cable routes
- Measure from the distribution board to each room along the proposed route, including rises and drops.
- Add the route within the room to the furthest point and separate switch cable. List each appliance using electrical input ratings.
Metric: All routes are in metres, cable cross-sections in mm² and appliance input power in watts.
Imperial: This planner uses metres and mm² throughout; convert feet to metres by multiplying by 0.3048 before entering routes.
How to plan your electrical work
- Choose the country and confirm the supply arrangement.
- Add each room, light fitting, socket position and appliance.
- Check nameplate powers, power factors, manufacturer limits and routed cable lengths.
- Review the room circuits, voltage drop and cable takeoff with your electrician.
Assumptions
These are the defaults behind a new calculation. You can change the relevant values in the calculator; the result always shows the assumptions it used.
Preliminary sizing scope: 200–250 V single-phase copper radial circuits
Our default — Mauritius and UK selections use a conservative IEC reference estimate, not national certification. Other countries retain quantities and loads only.
Electrical estimate formulas
Load current = electrical input watts ÷ (voltage × power factor).
Candidate breaker ≥ full-load current; corrected cable capacity ≥ candidate breaker.
Voltage drop uses the single-phase loop impedance and the full routed length; upstream drop uses part of the budget.
Order length = sum of each circuit route and switch cable × (1 + allowance / 100).
Example: a 2,300 W appliance
At 230 V and power factor 1, a 2,300 W appliance draws 10 A. A 10 m DB route plus 5 m inside the room needs 16.5 m of cable with a 10% ordering allowance. Cable selection still depends on installation conditions and voltage drop.
Frequently asked questions
Does a kitchen need a bigger breaker than a bedroom?
Room names do not determine ratings. A kitchen usually has more high-power appliances, so it often needs several circuits. List each appliance; fixed cooking, heating and laundry loads can have dedicated circuits.
Why does a longer run need a larger cable?
Longer cables lose more voltage at the same current. A cable can pass the thermal check but fail the voltage-drop check, so both are tested.
Are these installation instructions?
No. These are planning quantities and preliminary candidates. An electrician must verify national rules, fault protection, earthing, RCD selection, starting currents and manufacturer requirements.
Can I calculate any appliance?
Choose a preset or add a custom appliance. Replace example watts and power factor with electrical input data. Enter manufacturer minimum circuit current and maximum breaker limits for a dedicated load when supplied.
Which countries have automatic sizing?
Mauritius and UK selections offer the disclosed IEC reference estimate for single-phase radial circuits. France, Australia, United States and Other provide room quantities and loads, with automatic sizing withheld pending a local design.
Does this select a main breaker or three-phase supply?
No. Connected loads are not diversified maximum demand. Three-phase balancing, split-phase systems, ring circuits and service protection require a separate design.