- Correction product (Ca·Cg·Ci·Cf)1
- Required tabulated capacity It32A
- Minimum cable size4mm²
- Cable capacity Iz (this method)36A
- Voltage drop0V
- Voltage drop0%
- Sized oncurrent capacity
// Estimate only — verify before quoting
Cable Size (Full BS 7671 Workflow) Calculator
Sizes a Twin & Earth circuit from design current, protective device, installation method, correction factors (Ca·Cg·Ci·Cf) and voltage drop — all in one. Guidance only; verify against BS 7671.
Read the guide
How to Size a Cable (BS 7671)
Where to buy
Got your quantities? Compare prices and order the materials from the UK's biggest merchants.
Affiliate links — we may earn a small commission if you buy through them, at no extra cost to you. It keeps TradesMate's calculators free.
Browse the full shop →Frequently asked questions
How do I use the cable size (full bs 7671 workflow) calculator?
Enter your measurements and options into the Cable Size (Full BS 7671 Workflow) above and the result updates instantly. Sizes a Twin & Earth circuit from design current, protective device, installation method, correction factors (Ca·Cg·Ci·Cf) and voltage drop — all in one. Guidance only; verify against BS 7671.
Is the cable size (full bs 7671 workflow) calculator free to use?
Yes — every TradesMate calculator is free to use with no sign-up. Save quotes and use the full estimator with a free trial.
Are the results accurate enough to quote from?
The figures are reliable estimates based on standard UK trade practice. Always allow for wastage and verify against current material prices before quoting a customer.
Related calculators
Turn your numbers into a winning quote
Use the full TradesMate estimator to build branded, professional quotes in minutes.
Open the estimator →