Cable Cross-Section Calculator by Current and Power: Voltage Drop Calculation, SWG to AWG to mm² Converter

Wire Gauge and Voltage Drop Calculator

Sizing by both criteria at once — heating per DIN VDE 0298-4 and voltage drop per HD 60364-5-52 Annex G. Result in mm², AWG and SWG.

Recommended size

—mm²

Permissible load

AWG — SWG —

for the selected size and conditions

Voltage drop0 V · 0%

Voltage at load0 V

Power loss0 W

Heat output0 W/m

Ampacity Iz0 A

Conductor temperature0 °C

Iz = Itable · f1 · f2 · f4 —

Custom size — mm²

Compliance check

Load current Ib 5 A

Run length 3 m

One way — the return conductor is included automatically

Voltage 24 V

Current type

Material

Power factor cos φ 1.00

Reactance of 0.08 mΩ/m is included per HD 60364-5-52 Annex G

Not applicable to direct current

Installation method

Reference methods A2 / B2 / C / E per DIN VDE 0298-4, Table 2

Ambient temperature 30 °C

Grouping f2 = 1.00

Circuits alongside 1

Tables 22 and 28 of DIN VDE 0298-4. A neutral of a balanced circuit is not counted, PE never is.

Design margin +25%

Not a requirement of the standard but a designer's margin. Applied to size selection only.

Permissible drop 3%

3% per DIN 18015-1 for dwellings, 5% for other circuits per Annex G

Short-circuit withstand k = 115

Fault current, kA

Disconnection time, s

Adiabatic minimum0 mm²

Limit time0 s

S ≥ √(I²t)/k per IEC 60364-4-43, Table 43.1

Neutral conductor N 3-phase

—mm²

AWG—

Neutral current0 A

Factor f41.00

Third harmonic content

Appears when three-phase supply is selected

Wire size converter: mm² ↔ AWG ↔ SWG

converter

Enter a value in any field — the other two are recalculated automatically.

mm²

Metric cross-section

AWG

American Wire Gauge

SWG

British Standard Wire Gauge

Conductor diameter0 mm

Nearest standard size— mm²

Iz, clipped to a wall (C)— A

Iz, in conduit or trunking (B2)— A

Copper resistance at 20 °C0 mΩ/m

Iz is given for copper with PVC insulation, two loaded conductors, 30 °C, no grouping. A dash means the size falls outside the table of the standard — no extrapolation is done here.

Reference calculation. The size is chosen by the greater of two criteria: permissible heating per DIN VDE 0298-4:2023-06 (Tables 2 and 11 with factors from Tables 17, 22, 28 and B.1) and permissible voltage drop per HD 60364-5-52 Annex G. Heat output is given per metre of the run. Fixed wiring is subject to local regulations, and the protective device is rated to the cable, not to the load.