12V Cable Size Calculator | Falcon Overland

CABLE SIZING GUIDE

Choose the right cable for your 12V install

Not sure what cable size you need? Use Falcon Overland’s free cable sizing calculator to help plan your 12V wiring. Whether you’re building a campervan, upgrading your caravan or setting up your 4WD, start with your cable sizing below.

Your setup

Between chart values? We round both length and load up to the next chart entry.

Your chart result

mm²

Chart length

Chart load

Chart voltage drop

Fuse sizes by type

Cable’s chart current rating:

Minimum fuse sizes in the supplied chart at 40°C. Choose the type that matches your fuse holder, then verify the exact fuse specification.

Mini fuse

Maxi fuse

Midi fuse

Mega fuse

Chart conditions

XLPE-X110 cable at 40°C, touching a surface and close to other cables. The supplied chart does not state system voltage or define one-way versus total circuit length. Confirm both conventions before applying the result.

View the cable and fuse chart

Cable sizes are conductor area in mm²; fuse columns show marked amperage in A. Highlighted cells are your selected chart entries. Scroll sideways on smaller screens.

XLPE-X110 reference · cable sizes in mm² · fuse minimums in A at 40°C
Load	<1.0 m	1.5 m	2.0 m	3.0 m	4.0 m	5.0 m	6.0 m	10.0 m	Mini fuse	Maxi fuse	Midi fuse	Mega fuse
5 A	1	1.5	1.5	2.5	4	4	6	10	7.5	—	—	—
10 A	1.5	2.5	4	4*	6	10	10	16	15	20	23	—
15 A	2.5	4	6	6*	10	10*	16	25	20	20	23	—
20 A	4	6	6	10	16	16	25	35	25	20	23	40
25 A	4	6	10	16	16	25	25	35	—	30	30	40
30 A	6	10	10	16	25	25	25	50	—	35	40	60
40 A	6	10	16	25	25	35	35	70	—	50	50	60
50 A	10	16	16	25	35	35	50	70	—	60	60	80
60 A	10	16	25	25	35	50	50	95	—	70	70	80
80 A	16	25	25	35	50	70	70	120	—	—	100	100
100 A	16	25	35	50	70	70	95	150	—	—	125	125
125 A	25	35	35	70	70	95	120	185	—	—	175†	175
150 A	35	35	50	70	95	120	150	240	—	—	—	200
200 A	50	50	70	95	120	150	185	—	—	—	—	300†
250 A	70	70	70	120	150	185	240	—	—	—	—	350†
275 A	70	70	95	120	185	240	240	—	—	—	—	450†
300 A	95	95	95	150	185	240	240*	—	—	—	—	500†
350 A	95	95	95	150	240	240	—	—	—	—	—	—

* The source lists 3.1% voltage drop for these cells, above its 3% heading. A dash means no size is supplied. Exactly 1.0 m uses the 1.5 m column because the first column is labelled <1.0 m.

† The referenced Littelfuse MIDI 150–200 A and MEGA 300–500 A ratings are for short-circuit protection only; check overload protection. Fuse minimums come from the supplied chart, not a manufacturer-approved design for your installation.

How to use this guide

Use maximum load. Use the highest current your circuit must carry, including relevant starting loads. The calculator selects the next listed load when yours falls between rows.

Check the cable specification. mm² means conductor area, not overall cable diameter or an automotive cable trade size. This chart applies to its stated XLPE-X110 cable and installation conditions.

Treat voltage drop as a chart value. The displayed percentage comes from the selected chart cell; it is not a calculation for your actual installation. Some entries reach or exceed 3%. Critical loads need their voltage-drop limit checked.

Verify circuit protection. Fuse sizes are the chart’s listed alternatives for your selected load row. Values above the selected cable’s chart current rating are flagged. Verify the actual fuse, holder, continuous-current capability, overload protection and installation conditions; this tool does not establish AS/NZS compliance.