Which is better for a 20-amp outlet circuit?

The 12/2. It matches a 20A breaker and standard receptacles. The 10/2 works electrically but is stiffer and wastes box space.

Can I use 10/2 for a water heater?

Yes, if the heater is a 240V unit without a neutral and draws 30A or less. Check the nameplate and local code first.

Which is easier to install?

The 12/2. It is lighter, thinner and bends more easily. The 10/2 needs more force and a wider bend radius.

Do both have a ground wire?

Yes. Both are two-conductor NM-B with a bare ground, rated 600V and 90°C.

Is the 10/2 worth stepping up to?

Only if the circuit needs 30A. For 15A or 20A branch circuits, the 12/2 is the right choice and easier to work with.

Southwire Romex SIMpull 12/2 NM-B Wire vs 10/2 NM-B Wire with Ground

Buy the 12/2 for standard 20-amp household branch circuits: outlets, switches, lights and kitchen counter runs. Buy the 10/2 for 30-amp circuits, mainly 240V loads like water heaters, baseboard heaters and window AC units that need no neutral. The 10/2 is thicker copper with a higher ampacity, so it is stiffer to pull and harder to bend in tight boxes. Owners of both rate them well for solid copper, easy stripping and a jacket that pulls cleanly.

Choose the Southwire 12/2 50' if you are wiring 15- or 20-amp circuits and want a manageable coil that bends easily into boxes and along joists.
Choose the 10/2 NM-B if the circuit is rated 30 amps, such as a 240V water heater, baseboard heater or window AC, and you can handle the stiffer cable.

Prices

Southwire Romex SIMpull 12/2 NM-B Wire: $32.99 at Amazon (checked today)
10/2 NM-B Wire with Ground: $1.44 at NassauNationalCable (checked today)
Difference: the 10/2 NM-B Wire with Ground is $31.55 cheaper than the Southwire Romex SIMpull 12/2 NM-B Wire today

	Southwire Romex SIMpull 12/2 NM-B Wire	10/2 NM-B Wire with Ground
Wire gauge	12 AWG copper	10 AWG copper
Ampacity	20 amps on a 20A breaker	30 amps on a 30A breaker
Typical use	120V outlets, switches, lighting	240V fixed appliances without a neutral
Flexibility	Easier to bend and fold into boxes	Stiffer, needs wider bend radius
Weight per 1,000 ft	About 87 lb	About 123 lb
Outer diameter	About 0.422 in	About 0.493 in
Voltage and temperature rating	600V, 90°C	600V, 90°C
Jacket color	Yellow	Orange

Spec	Southwire Romex SIMpull 12/2 NM-B Wire	10/2 NM-B Wire with Ground
Conductor Size	12 AWG	10 AWG
Weight	1.81 kg	123 Lb/MFt
Wire Gauge	12 gauge	10 gauge
size	EA	—
color	Black	—
Conductor Number	2	—
Conductor Strands	Solid	—
Ground Size	1x12	—
Approx. OD	0.422 inches	—
Approx. Weight	87 lbs/1000'	—
Voltage Rating	600 volts	—
Jacket Color	YELLOW	—

Spec	Southwire Romex SIMpull 12/2 NM-B Wire	10/2 NM-B Wire with Ground
Length	50 ft.	—
Maximum Temperature	90 deg C	—
Wire/Cable Type	NM-B	—
Number of Conductors	—	2
Stranding	—	Solid
Conductor Material	—	Copper
Voltage	—	600 Volt
Temperature Rating	—	90 degrees C
Insulation Material	—	PVC
Jacket Material

Southwire Romex SIMpull 12/2 NM-B Wire vs 10/2 NM-B Wire with Ground

Prices

Southwire Romex SIMpull 12/2 NM-B Wire vs 10/2 NM-B Wire with Ground

Prices

Southwire Romex SIMpull 12/2 NM-B Wire

10/2 NM-B Wire with Ground

What separates them

Price history

Prices at every store

Southwire Romex SIMpull 12/2 NM-B Wire

10/2 NM-B Wire with Ground

Specs compared

What reviewers say

Southwire Romex SIMpull 12/2 NM-B Wire

10/2 NM-B Wire with Ground

Questions and answers

Ask our shopping agent

Buying guides that pick them

Southwire Romex SIMpull 12/2 NM-B Wire

10/2 NM-B Wire with Ground

What separates them

Price history

Prices at every store

Southwire Romex SIMpull 12/2 NM-B Wire

10/2 NM-B Wire with Ground

Specs compared

What reviewers say

Southwire Romex SIMpull 12/2 NM-B Wire

10/2 NM-B Wire with Ground

Questions and answers

Ask our shopping agent

More comparisons

Buying guides that pick them