Appliances & Utilities calculator
What Extension Lead Length Do I Need?
Calculate extension lead length and current check using outlet-to-appliance route, service slack, and connected load watts.
Enter your measurements
For what extension lead length do i need, use the real measurements for outlet-to-appliance route, service slack, and connected load watts. The calculator then reports extension lead length and current check and keeps any manufacturer- or rule-specific checks separate.
- Outlet-to-appliance route — Required
- Service slack — Required
- Connected load watts — Required
- Supply voltage — Required
- Lead manufacturer rated current — Required
Extension lead length and current check
Enter the measurements above to calculate extension lead length and current check.
How the calculation works
Calculation used: requiredLength=routeLength+slack; loadCurrent=loadWatts/supplyVoltage; currentPass=loadCurrent≤leadRatedCurrent. The reported result is extension lead length and current check.
Worked example
Example: Outlet-to-appliance route = 450 cm; Service slack = 5 cm; Connected load watts = 1800 W; Supply voltage = 230 V; Lead manufacturer rated current = 13 A. Result: Fits; Load Current = 7.83 A; Required Length = 455 cm.
Before you decide
Enter the dimensions that will exist in real use, not an approximate catalogue category. This page calculates the stated geometry or quantity only; product-specific construction or installation details can still affect the final choice. For what extension lead length do i need, the limiting result on this page is extension lead length and current check.
Direct measurement/geometry calculation. No external reference is required for the arithmetic itself; the result is derived only from the user-entered measurements and the formula stored in calculationLogicJson.
Frequently asked questions
How does the Extension Lead Length Fit | What Fits? calculator work?
It uses requiredLength=routeLength+slack; loadCurrent=loadWatts/supplyVoltage; currentPass=loadCurrent≤leadRatedCurrent. The result is extension lead length and current check.
Which measurements or specifications do I need?
Use these inputs: Outlet-to-appliance route, Service slack, Connected load watts, Supply voltage, Lead manufacturer rated current. Measure or copy the values from the exact product/specification rather than guessing.
Is the result a guarantee that the product will fit or be suitable?
No. The calculator answers the stated extension lead length and current check question. Manufacturer instructions, safety rules, certification, installation tolerances or brand-specific size charts can impose additional requirements.