WIRE GAUGE CONVERSION TOOL
Wire Gauge mm² to AWG Converter: Full Conversion Chart, Formula and Safe-Substitute Guide
Convert between mm² and AWG in both directions, print the full AWG reference table, and see why 2.5 mm² is 14 AWG by name but 12 AWG by safety. Round up in copper, every time.
TWO DIRECTIONS, ONE RULE
How to Use the mm² to AWG Converter
Enter a value in either field and the converter returns the other — the exact area, the conductor diameter, and the safe substitute when you must replace one system with the other.
Choose the
Direction
Switch between mm² → AWG and AWG → mm². The converter recalculates instantly.
Enter the
Known Value
Type a metric area such as 2.5 mm² or an AWG size such as 10. Decimals are accepted.
Read the
Exact Result
The converter shows the exact cross-sectional area and conductor diameter from the AWG formula.
Check the
Safe Substitute
The converter reports the next common size that carries at least as much copper as the value you entered.
Round Up,
Never Down
When the installation code governs, the safe substitute is the smaller AWG number, i.e. the larger conductor.
WIRE GAUGE CONVERTER
Convert Between mm² and AWG
AWG is a diameter-based, inverse-logarithmic scale and mm² is a cross-sectional area, so the two systems never align exactly. This converter returns the exact area and diameter, the nearest AWG, and the safe substitute when you must replace one with the other.
INPUT VALUE
Wire Size
mm²
Example: 2.5 for a 2.5 mm² metric conductor.
AWG
Example: 10 for 10 AWG. AWG runs inversely — a smaller number means a thicker conductor.
CALCULATED RESULT
Live Result
Nearest Standard AWG
13
AWG
Closest integer AWG by cross-sectional area. AWG runs inversely, so a smaller number is a thicker conductor.
Exact Area
2.500 mm²
Conductor Diameter
1.784 mm
Safe Substitute
13 AWG
Substitute Area
2.62 mm²
EQUATION
d = 0.127 × 92^((36 − AWG) / 39)
Area = π/4 × d²
A
2.500 mm²
Entered area
d
1.784 mm
Diameter
AWG
13
Nearest gauge
Every “equivalent” is a nearest-nominal choice.
From 1.5 mm² upward, the AWG stamped on a cable usually carries less copper than the metric size it stands for. Round up in copper, in both directions.
QUICK REFERENCE
Common Tool-Cable Conversions
Reference values only. The “common equivalent” is a naming convention, not an equality. For safety-critical or code-governed work, confirm against the governing standard and the cable manufacturer’s data sheet.
1.5 mm²
16 AWG
2.5 mm²
14 AWG
4 mm²
12 AWG
6 mm²
10 AWG
10 mm²
8 AWG
16 mm²
6 AWG
AWG REFERENCE TABLE
Wire Gauge Conversion Chart: mm² to AWG
FORMULA
d = 0.127 × 92^((36 − AWG) / 39)
The table below is the full AWG reference, from 4/0 down to 30 AWG, with diameter and cross-sectional area from ASTM B258. The formula above is the definition of the AWG scale; the areas in the right-hand column are the ASTM standard values rather than formula output.
| AWG | Diameter (mm) | Cross-sectional area (mm²) |
|---|---|---|
| 4/0 | 11.68 | 107 |
| 3/0 | 10.40 | 85.0 |
| 2/0 | 9.27 | 67.4 |
| 1/0 | 8.25 | 53.5 |
| 1 | 7.35 | 42.4 |
| 2 | 6.54 | 33.6 |
| 3 | 5.83 | 26.7 |
| 4 | 5.19 | 21.2 |
| 5 | 4.62 | 16.8 |
| 6 | 4.11 | 13.3 |
| 7 | 3.67 | 10.6 |
| 8 | 3.26 | 8.37 |
| 9 | 2.91 | 6.63 |
| 10 | 2.59 | 5.26 |
| 11 | 2.30 | 4.17 |
| 12 | 2.05 | 3.31 |
| 13 | 1.83 | 2.62 |
| 14 | 1.63 | 2.08 |
| 15 | 1.45 | 1.65 |
| 16 | 1.29 | 1.31 |
| 17 | 1.15 | 1.04 |
| 18 | 1.02 | 0.823 |
| 19 | 0.91 | 0.653 |
| 20 | 0.81 | 0.518 |
| 21 | 0.72 | 0.410 |
| 22 | 0.64 | 0.326 |
| 23 | 0.57 | 0.258 |
| 24 | 0.51 | 0.205 |
| 25 | 0.455 | 0.162 |
| 26 | 0.405 | 0.129 |
| 27 | 0.361 | 0.102 |
| 28 | 0.321 | 0.081 |
| 29 | 0.286 | 0.064 |
| 30 | 0.255 | 0.051 |
!
Reference values, not a manufacturer specification. AWG is defined by ASTM B258; metric conductor sizes by IEC 60228. Confirm the current edition of the applicable standard before using these values for design or purchase specifications.
THE PATTERN IS THE POINT
Common Metric Equivalents, Stated Honestly
The table below is the cable industry’s “common equivalent” for the metric sizes most relevant to electrical tooling, power cords, extension leads, panel wiring and cable cutting. The last column states whether that common AWG carries more or less copper than the metric size it is stamped against.
| Metric size (mm²) | Common AWG equivalent | Exact area of the AWG (mm²) | Copper versus metric |
|---|---|---|---|
| 0.5 | 20 AWG | 0.518 | Slightly more |
| 0.75 | 18 AWG | 0.823 | Slightly more |
| 1.0 | 17 AWG | 1.04 | Slightly more |
| 1.5 | 16 AWG | 1.31 | Less |
| 2.5 | 14 AWG | 2.08 | Less |
| 4 | 12 AWG | 3.31 | Less |
| 6 | 10 AWG | 5.26 | Less |
| 10 | 8 AWG | 8.37 | Less |
| 16 | 6 AWG | 13.3 | Less |
| 25 | 4 AWG | 21.2 | Less |
| 35 | 2 AWG | 33.6 | Less |
| 50 | 1/0 AWG | 53.5 | More |
At 1.0 mm² and below, the common equivalent is safe.
From 1.5 mm² upward, it is not.
That is not a mistake in the table — it is why the round-up rule in the next section exists. Sources also disagree on a few of these “equivalents”: 1.5 mm² appears against both 16 AWG and 15 AWG, and 50 mm² against both 1/0 and 1 AWG. The differences come from whether a chart is reporting the nearest exact area, the nearest common stock gauge, or a safe substitute. This page reports the common stock equivalent and states the copper direction, which is the honest way to resolve the disagreement.
THE ROUND-UP RULE
Closest Gauge vs Safe Substitute
When you replace a metric conductor with an AWG one, round up in copper — choose an AWG whose cross-sectional area is equal to or greater than the metric area. This is the difference between a “closest” equivalent and a safe one, and it is the rule most conversion charts leave out.
WORKED EXAMPLE
2.5 mm² · replacement in AWG
Closest by exact area
13 AWG · 2.62 mm²
Common equivalent
14 AWG · 2.08 mm²
Copper versus 2.5 mm²
≈ 17% less
Safe substitute
12 AWG · 3.31 mm²
SAME METRIC SIZE · THREE ANSWERS
Nearest exact
13 AWG
2.62mm²
VS
Safe substitute
12 AWG
3.31mm²
12 AWG
the next commonly stocked gauge that carries at least as
much copper as 2.5 mm²
| Metric size | Common equivalent | Area of equivalent | Safe substitute (next common gauge up) |
|---|---|---|---|
| 1.5 mm² | 16 AWG | 1.31 mm² | 14 AWG (2.08 mm²) |
| 2.5 mm² | 14 AWG | 2.08 mm² | 12 AWG (3.31 mm²) |
| 4 mm² | 12 AWG | 3.31 mm² | 10 AWG (5.26 mm²) |
| 6 mm² | 10 AWG | 5.26 mm² | 8 AWG (8.37 mm²) |
| 10 mm² | 8 AWG | 8.37 mm² | 6 AWG (13.3 mm²) |
→
The same rule runs in the opposite direction. 10 AWG is exactly 5.26 mm², and the next standard metric size up is 6 mm². Whenever you must substitute in either direction, round toward more copper, not less.
TWO SYSTEMS, TWO DEFINITIONS
AWG vs mm²: What the Conversion Actually Means
KEY POINT
No exact conversion exists
The confusion between the two systems comes from the fact that they measure different things. AWG is a gauge number assigned to a diameter. It is logarithmic and inverted: each three-gauge step roughly doubles or halves the cross-sectional area, and a smaller number means a thicker wire. mm² states the cross-sectional area of the conductor directly. The two grids are defined independently, so a metric area almost never lands exactly on an AWG area.
01
AWG measures diameter
A US standard that sizes wire by diameter on an inverse, logarithmic scale. Smaller number, thicker wire.
02
mm² measures area
A metric measure of the conductor’s cross-sectional area. Larger number, thicker wire.
03
They never align exactly
One is diameter-based and the other area-based, so every conversion is a nearest-nominal approximation.
A chart that shows a clean “2.5 mm² = 14 AWG” is rounding, not equating.
The nearest AWG by exact area is often an uncommon odd gauge, which is why the cable industry stamps the nearest common gauge instead — and that common gauge is usually on the smaller side of the metric size.
STRANDED VS SOLID
Same Gauge, Two Outer Diameters
AWG specifies the conductor’s area, which is the same whether the wire is solid or stranded. The outer diameter is a different matter. Stranded wire is thicker overall than solid wire at the same gauge, because the individual strands leave small gaps between them.
For a cable cutter, a terminal, a ferrule or a gland, the outer diameter is the number that matters, not the nominal area. Two 2.5 mm² conductors, one solid, one finely stranded, will not take the same terminal or the same cutter jaw setting. If you work on insulated or live conductors, the safety side of cable sizing and tooling is covered in the IEC 60900 insulated tools reference.
01
Nominal area
Same for solid and stranded
02
Outer diameter
Larger when stranded
03
Tooling
Cutter jaw, terminal, gland
04
Current rating
Follows area, not OD
!
Does AWG measure diameter or area?
AWG is assigned by diameter, but the electrically meaningful figure is the cross-sectional area that diameter produces. A fixed AWG has a fixed nominal area, whether the conductor is solid or stranded — only the outside diameter changes with stranding.
AMPACITY NOTE
A Note on Ampacity
REFERENCE
NEC Table 310.16
Current-carrying capacity, ampacity, is the reason the round-up rule matters, but it is not a fixed property of the wire size alone. It depends on the insulation temperature rating, the number of conductors in the run, the ambient temperature, and how the cable is installed.
As a reference, the US table most often cited is NEC NFPA 70 Table 310.16, which rates copper conductors at a stated ambient temperature and conductor count. Metric installs are typically sized against IEC 60228 conductor classes and the local wiring regulations. The two do not map one-to-one, which is exactly why a conversion chart should point you to the code that governs the installation rather than hand you a single ampacity number.
!
Ampacity figures are reference values under stated conditions, not universal ratings. Select the conductor size against the governing installation code for the market and the application, and confirm against the cable manufacturer’s data sheet.
FREQUENTLY ASKED QUESTIONS
Common Questions, Answered
What is the difference between AWG and mm²?
AWG is a US standard that sizes wire by diameter on an inverse, logarithmic scale, while mm² is a metric measure of cross-sectional area. Because one is diameter-based and the other area-based, the two scales never align exactly, and every conversion is a nearest-nominal approximation rather than an equality.
Is 2.5 mm² the same as 14 AWG?
Not exactly. 2.5 mm² is commonly labeled 14 AWG, but 14 AWG is 2.08 mm², about 17% less copper. If the AWG conductor must meet the 2.5 mm² rating, step up to 12 AWG (3.31 mm²).
How do I convert mm² to AWG?
Find the nearest AWG by cross-sectional area, then round up in copper: choose an AWG whose area is equal to or greater than the metric size. For example, 2.5 mm² rounds to 12 AWG rather than the commonly stamped 14 AWG.
What is 14 AWG in mm²?
14 AWG has a cross-sectional area of 2.08 mm². The next standard metric size up is 2.5 mm², which is the size to specify if the conductor must carry at least as much current as 14 AWG.
Which is thicker, 12 AWG or 14 AWG?
12 AWG is thicker. AWG runs inversely, so a smaller number means a larger diameter and a larger cross-sectional area. 12 AWG is 2.05 mm in diameter and 3.31 mm² in area; 14 AWG is 1.63 mm and 2.08 mm².
Does AWG measure diameter or area?
AWG is assigned by diameter, but the electrically meaningful figure is the cross-sectional area that diameter produces. A fixed AWG has a fixed nominal area, whether the conductor is solid or stranded — only the outside diameter changes with stranding.
FROM SIZE TO TOOL
From Cable Size to Cable Tools
This is the step most conversion pages stop short of, and it is the one that matters for anyone actually working the cable. Once a conductor is sized, the next question is what you work it with. A cable cutter is rated for a conductor range, and matching the tool to the cross-section is the difference between a clean cut and a crushed or splayed end. The same applies to wire strippers, crimping tools and ferrules.
!
Verify before you claim
Cable cutters and insulated tools are offered against the relevant standards framework, and applicability is product- and market-specific. Confirm the exact standard, certificate, test report and SKU for your market before making a compliance claim.
If you are specifying cable cutters, strippers or insulated tools against a conductor range.
Send us the range and your target market, and we will quote it factory-direct against a sample. The electrical cable cutters range is the place to start for insulated electrical cable work, and the general cable and wire cutters range covers the wider cutting task.
Range
Conductor
Match the tool to the area
Outer diameter
Stranded vs solid
Cutter jaw and gland
Standard
Confirm
Standard, certificate, SKU
Market
State it
Applicability varies
RELATED TOOL RESOURCES
Continue Reading
CONCLUSION
The Converter Answers the Lookup. Three Rules Make It Reliable.
AWG and mm² measure different things.
AWG is a diameter-based, inverse-logarithmic scale; mm² is cross-sectional area. There is no exact conversion, only a nearest-nominal choice.
The common “equivalent” is a naming convention, not an equality.
From 1.5 mm² upward, the stamped AWG equivalent carries less copper than the metric size it represents, which is why you round up.
Round up in copper, in both directions.
2.5 mm² is 14 AWG by name but 12 AWG by safety; 10 AWG is 5.26 mm², which rounds up to 6 mm².
The outside diameter is a tooling question.
Stranded and solid conductors of the same gauge have the same area but different outer diameters, and the cutter, terminal or gland cares about the diameter.
Ampacity follows the installation code, not the gauge alone.
The size is a reference; the governing code decides the rating. Confirm the code before you commit.
Specifying cable cutters or insulated tools?
Tell us the conductor sizes, the set configuration and the target market, and we will quote the program factory-direct from our own tooling. Ask for a sample before the order if you would rather prove the specification first.
Frequently Asked Questions (FAQs)
Frequently Asked Questions. For more information, our customer support team is ready to assist you.
What is the difference between AWG and mm²?
AWG is a US standard that sizes wire by diameter on an inverse, logarithmic scale, while mm² is a metric measure of cross-sectional area. Because one is diameter-based and the other area-based, the two scales never align exactly, and every conversion is a nearest-nominal approximation rather than an equality.
Is 2.5mm² the same as 14 AWG?
Not exactly. 2.5 mm² is commonly labeled 14 AWG, but 14 AWG is 2.08 mm², about 17% less copper. If the AWG conductor must meet the 2.5 mm² rating, step up to 12 AWG (3.31 mm²).
How do I convert mm² to AWG?
Find the nearest AWG by cross-sectional area, then round up in copper: choose an AWG whose area is equal to or greater than the metric size. For example, 2.5 mm² rounds to 12 AWG rather than the commonly stamped 14 AWG.
What is 14 AWG in mm²?
14 AWG has a cross-sectional area of 2.08 mm². The next standard metric size up is 2.5 mm², which is the size to specify if the conductor must carry at least as much current as 14 AWG.
Which is thicker, 12 AWG or 14 AWG?
12 AWG is thicker. AWG runs inversely, so a smaller number means a larger diameter and a larger cross-sectional area. 12 AWG is 2.05 mm in diameter and 3.31 mm² in area; 14 AWG is 1.63 mm and 2.08 mm².
Does AWG measure diameter or area?
AWG is assigned by diameter, but the electrically meaningful figure is the cross-sectional area that diameter produces. A fixed AWG has a fixed nominal area, whether the conductor is solid or stranded, only the outside diameter changes with stranding.