MM² to AWG Calculator with Wire Size Comparison

Conversion Results

Current and ampacity values are engineering estimates, not code approvals. Installation method, insulation, ambient conditions, terminals, and local rules can change safe limits. Verify final conductor selection with a qualified professional before installation.

Nearby Standard Sizes

AWG	Area (mm²)	Diameter (mm)	Circular mils	Resistance (Ω/km)	Difference

Calculator Inputs

Area to AWG AWG to area

Conductor area

Enter a positive conductor cross-sectional area.

Area unit

AWG size

Standard-size selection

Decimal precision

Conductor Properties

Conductor material

Conductor construction

Conductor temperature (°C)

Electrical Estimate Options

Wire length

Length unit

Length basis

Load current (A)

System voltage (V)

Circuit type

Allowed voltage drop (%)

Design current density (A/mm²)

A user-selected engineering target, not a code ampacity.

Current-carrying conductors

Formula Used

AWG follows a logarithmic diameter progression with ninety-two size ratio. Area comes from the equivalent circular conductor diameter. These formulas compare nominal areas across standard gauge sizes.

d(in) = 0.005 × 92^((36 − AWG) / 39)

A(mm²) = π ÷ 4 × (25.4 × d(in))²

AWG = 36 − 19.5 × log(A ÷ 0.012668) ÷ log(92)

R = ρ × L ÷ A

Vdrop(single-phase or DC) = 2 × I × L × Rper-meter

Vdrop(three-phase) = √3 × I × L × Rper-meter

How to Use This Calculator

Select a conversion direction, then enter area or AWG. Add conductor and circuit details for advanced estimates. Review nearby sizes before choosing a practical installation conductor.

Choose area-to-AWG or AWG-to-area conversion.
Select the input unit and rounding preference.
Choose copper or aluminum, plus conductor construction.
Enter circuit details for voltage-drop and power-loss estimates.
Calculate, compare nearby sizes, then export results.

Example Conversion Data

Entered area	Approximate AWG	Nearest standard size	Standard area
0.50 mm²	20.15	20 AWG	0.518 mm²
0.75 mm²	18.40	18 AWG	0.823 mm²
1.00 mm²	17.16	17 AWG	1.038 mm²
1.50 mm²	15.41	15 AWG	1.650 mm²
2.50 mm²	13.21	13 AWG	2.624 mm²
4.00 mm²	11.18	11 AWG	4.172 mm²
6.00 mm²	9.43	9 AWG	6.634 mm²
10.00 mm²	7.23	7 AWG	10.549 mm²
16.00 mm²	5.20	5 AWG	16.773 mm²
25.00 mm²	3.28	3 AWG	26.670 mm²

AWG Reference Table

AWG	Diameter (mm)	Diameter (in)	Area (mm²)	Circular mils	Copper Ω/km	Aluminum Ω/km
0000	11.6840	0.46000	107.21930	211,600	0.1608	0.2636
000	10.4049	0.40964	85.02877	167,806	0.2028	0.3324
00	9.2658	0.36480	67.43088	133,077	0.2557	0.4192
0	8.2515	0.32486	53.47512	105,535	0.3224	0.5285
1	7.3481	0.28930	42.40770	83,693	0.4066	0.6665
2	6.5437	0.25763	33.63083	66,371	0.5127	0.8404
3	5.8273	0.22942	26.67046	52,635	0.6464	1.0597
4	5.1894	0.20431	21.15064	41,741	0.8152	1.3363
5	4.6213	0.18194	16.77322	33,102	1.0279	1.6851
6	4.1154	0.16202	13.30177	26,251	1.2961	2.1248
7	3.6649	0.14429	10.54878	20,818	1.6344	2.6794
8	3.2636	0.12849	8.36556	16,510	2.0609	3.3786
9	2.9064	0.11442	6.63419	13,093	2.5988	4.2604
10	2.5882	0.10190	5.26115	10,383	3.2770	5.3722
11	2.3048	0.09074	4.17229	8,234	4.1323	6.7742
12	2.0525	0.08081	3.30877	6,530	5.2107	8.5421
13	1.8278	0.07196	2.62398	5,178	6.5706	10.7714
14	1.6277	0.06408	2.08091	4,107	8.2853	13.5825
15	1.4495	0.05707	1.65023	3,257	10.4476	17.1273
16	1.2908	0.05082	1.30870	2,583	13.1742	21.5971
17	1.1495	0.04526	1.03784	2,048	16.6123	27.2334
18	1.0237	0.04030	0.82305	1,624	20.9478	34.3407
19	0.9116	0.03589	0.65271	1,288	26.4147	43.3028
20	0.8118	0.03196	0.51762	1,022	33.3083	54.6038
21	0.7229	0.02846	0.41049	810	42.0009	68.8542
22	0.6438	0.02535	0.32553	642	52.9622	86.8235
23	0.5733	0.02257	0.25816	509	66.7841	109.4824
24	0.5106	0.02010	0.20473	404	84.2132	138.0548
25	0.4547	0.01790	0.16236	320	106.1909	174.0839
26	0.4049	0.01594	0.12876	254	133.9043	219.5157
27	0.3606	0.01420	0.10211	202	168.8502	276.8042
28	0.3211	0.01264	0.08098	160	212.9161	349.0437
29	0.2859	0.01126	0.06422	127	268.4823	440.1359
30	0.2546	0.01003	0.05093	101	338.5499	555.0012
31	0.2268	0.00893	0.04039	80	426.9036	699.8435
32	0.2019	0.00795	0.03203	63	538.3155	882.4864
33	0.1798	0.00708	0.02540	50	678.8033	1,112.7948
34	0.1601	0.00630	0.02014	40	855.9551	1,403.2084
35	0.1426	0.00561	0.01597	32	1,079.3395	1,769.4131
36	0.1270	0.00500	0.01267	25	1,361.0219	2,231.1887
37	0.1131	0.00445	0.01005	20	1,716.2170	2,813.4770
38	0.1007	0.00397	0.00797	16	2,164.1097	3,547.7290
39	0.0897	0.00353	0.00632	12	2,728.8919	4,473.6037
40	0.0799	0.00314	0.00501	10	3,441.0692	5,641.1101

Frequently Asked Questions

What is the difference between mm² and AWG?

Millimeters squared directly describe a conductor cross-sectional area. AWG represents diameter through a logarithmic gauge sequence. Both systems identify conductor size using different numerical conventions.

How does the calculator convert mm² to AWG?

The calculator converts area into an equivalent circular diameter. It then applies the standard logarithmic AWG relationship. Nearby standard sizes reveal practical choices around the result.

Why does a smaller AWG number mean larger wire?

AWG developed from repeated wire-drawing steps during manufacturing. More drawing operations produced thinner wires and higher numbers. Therefore lower gauge numbers indicate larger conductor cross-sections today.

Is every mm² value an exact AWG size?

No, metric areas rarely match nominal AWG sizes perfectly. The calculator reports an exact mathematical gauge before rounding. Compare differences before selecting the nearest usable standard conductor.

Should I choose a larger or smaller wire?

Larger conductors usually reduce resistance and voltage drop. Smaller conductors may overheat when improperly selected or installed. Use verified design requirements before making final installation decisions.

Does stranded wire have the same area as solid wire?

Equal nominal areas contain similar conductive material across constructions. Stranded bundles usually have larger overall bare diameters. Strand arrangement, compaction, and insulation determine actual finished dimensions.

Is copper AWG different from aluminum AWG?

AWG geometry remains unchanged for copper and aluminum conductors. Their resistivity values differ, affecting resistance and voltage drop. Aluminum commonly needs greater area for comparable electrical performance.

Can this calculator determine wire ampacity?

It provides a configurable current-density estimate for preliminary planning. Real ampacity depends on insulation, temperature, bundling, and installation. Always apply governing codes and verified manufacturer conductor data.

What is circular-mil area?

A circular mil is the area of one mil-diameter circle. Electrical industries use circular mils for conductor cross-sections. One circular mil equals approximately 0.000506707 square millimeters.

How accurate is the conversion?

The mathematical conversion is accurate for nominal AWG geometry. Manufactured conductors can vary within applicable dimensional and resistance tolerances. Stranded outside-diameter estimates remain approximate without detailed construction specifications.

Can I convert AWG back to mm²?

Yes, select AWG-to-area and choose the desired gauge. The calculator returns area, diameter, resistance, and nearby sizes. Export tools preserve those results for later comparison records.