Calculate voltage drop using an exact public Doncaster table for named 90°C single-core copper cables. No cable selection or compliance claim.
This is a deliberately narrow manufacturer-table lookup, not a generic BS 7671 cable calculator. It covers Doncaster 6491B and 6181XY 90°C thermosetting, unarmoured single-core copper cable in the listed arrangements and 1–16mm² rows. The user supplies the design limit; the tool does not pick one, recommend a larger cable or decide compliance. A competent electrical designer must still verify current-carrying capacity, conductor temperature, protective devices, correction factors, fault protection and withstand, CPC, earth-fault loop impedance, disconnection time, harmonics, special locations and the current manufacturer and BS 7671 requirements before installation or energisation.
Part of Builder Tools Calculators — construction tools for UK tradespeople.