Gauge to mm & Inches Conversion Chart 2026 – All Metals | SheetGauge

Gauge to mm & Inches Conversion Chart 2026 – All Sheet Metals

Complete gauge to mm and inches conversion for steel, galvanized, stainless steel, aluminium, and wire gauge (B&S / SWG). Updated 2026 reference for India.

India Reference 5 Metal Types mm & Inches Mobile Friendly

Gauge to mm & Inches Conversion Chart – All Metals

Select the metal type to view the correct gauge to mm conversion table. Each metal uses a different gauge standard — always confirm the material before using the table.

US Standard Gauge (USG) for mild steel / carbon steel sheet. Higher gauge = thinner sheet.

Gauge No. Thickness (Inches) Thickness (mm) Weight (kg/m²)
30.23916.07347.67
40.22425.69544.71
50.20925.31441.71
60.19434.93538.74
70.17934.55435.75
80.16444.17532.77
90.14953.79729.81
100.13453.41626.82
110.11963.03823.85
120.10462.65720.86
130.08972.27817.88
140.07471.89714.89
150.06731.70913.42
160.05981.51911.92
170.05381.36710.73
180.04781.2149.53
190.04181.0628.34
200.03590.9127.16
210.03290.8366.56
220.02990.7595.96
230.02690.6835.36
240.02390.6074.76
250.02090.5314.17
260.01790.4553.57
270.01640.4173.27
280.01490.3782.97
290.01350.3432.69
300.01200.3052.39

* Highlighted rows (10, 14, 18, 22) are most commonly stocked by Indian steel suppliers. Weight calculated at density 7.85 g/cm³. Standard: US Standard Gauge (USG) / ASTM. For MS sheet weight calculator, visit our MS Sheet Weight Calculator – India.

Galvanized (GI) steel gauge — slightly thicker than plain MS at same gauge due to zinc coating. Reference: IS 277:2018.

Gauge No. Thickness (Inches) Thickness (mm) Weight (kg/m²)
80.16814.27033.52
90.15323.89130.54
100.13823.51027.55
110.12333.13224.59
120.10842.75321.61
130.09342.37218.62
140.07851.99415.65
150.07101.80314.15
160.06351.61312.66
170.05751.46111.47
180.05161.31010.28
190.04561.1589.09
200.03961.0067.90
210.03660.9307.30
220.03360.8536.70
230.03060.7776.10
240.02760.7015.50
250.02470.6274.92
260.02170.5514.33
270.02020.5134.03
280.01870.4753.73
290.01720.4373.43
300.01570.3993.13

* GI gauge is thicker than MS gauge at same number due to zinc coating. Reference: IS 277:2018 (BIS). See full details on our Galvanized Steel Gauge Table page.

Stainless steel uses its own gauge standard. Density is slightly higher (~7.93–7.98 g/cm³ for SS 304/316).

Gauge No. Thickness (Inches) Thickness (mm) Weight SS 304 (kg/m²)
70.18754.76337.77
80.17194.36634.62
90.15633.96931.47
100.14063.57128.31
110.12503.17525.18
120.10942.77922.04
130.09382.38218.89
140.07811.98415.73
150.07031.78614.16
160.06251.58812.59
170.05631.42911.33
180.05001.27010.07
190.04381.1118.81
200.03750.9537.56
210.03440.8746.93
220.03130.7946.30
240.02500.6355.03
260.01880.4783.79
280.01560.3963.14
300.01250.3182.52

* Weight calculated using SS 304 density 7.93 g/cm³. For SS 316, multiply by 7.98/7.93. Highlighted rows are most stocked by Indian SS sheet suppliers (Mumbai, Ahmedabad, Chennai).

Aluminium sheet uses the Brown & Sharp (B&S) gauge system, same as wire. Density = 2.70 g/cm³.

Gauge No. (B&S) Thickness (Inches) Thickness (mm) Weight Al (kg/m²)
40.20435.18914.01
50.18194.62112.48
60.16204.11511.11
70.14433.6659.90
80.12853.2648.81
90.11442.9067.85
100.10192.5886.99
110.09072.3046.22
120.08082.0535.54
130.07201.8294.94
140.06411.6284.40
150.05711.4503.92
160.05081.2903.48
170.04531.1513.11
180.04031.0242.76
190.03590.9122.46
200.03200.8132.20
220.02530.6441.74
240.02010.5111.38
260.01590.4051.09
280.01260.3210.87
300.01000.2550.69

* Aluminium uses B&S gauge. Weight = Thickness (mm) × 2.70 kg/m² per mm. Highlighted rows are most commonly stocked in Indian aluminium sheet markets. External reference: IndiaMart – Aluminium Sheet Suppliers India.

B&S (Brown & Sharp) gauge is used for non-ferrous wire (copper, brass, aluminium). SWG (Standard Wire Gauge / Imperial) is used for steel and copper wire in India/UK.

Gauge No. B&S (mm) B&S (Inches) SWG (mm) SWG (Inches)
17.3480.2897.6200.300
26.5430.2587.0100.276
35.8270.2296.4010.252
45.1890.2045.8930.232
54.6210.1825.3850.212
64.1150.1624.8770.192
73.6640.1444.4700.176
83.2640.1294.0640.160
92.9060.1143.6580.144
102.5880.1023.2510.128
112.3040.0912.9460.116
122.0520.0812.6420.104
131.8290.0722.3370.092
141.6280.0642.0320.080
151.4500.0571.8290.072
161.2910.0511.6260.064
171.1490.0451.4220.056
181.0240.0401.2190.048
190.9120.0361.0160.040
200.8130.0320.9140.036
210.7240.0280.8130.032
220.6430.0250.7110.028
240.5110.0200.5590.022
260.4040.0160.4570.018
280.3300.0130.3760.015
300.2540.0100.3050.012
320.2000.0080.2740.011
340.1600.0060.2340.009
360.1300.0050.1930.008
380.1000.0040.1520.006

* B&S = Brown & Sharp (used for copper, brass, aluminium wire). SWG = Standard Wire Gauge / Imperial (used for steel wire, binding wire in India). Highlighted rows are most common in Indian electrical and construction wire markets.

How to Use the Gauge to mm Conversion Chart

Follow these steps to correctly convert gauge to mm or inches for your material

1

Identify Your Metal

Different metals use different gauge systems. Mild steel uses US Standard Gauge, aluminium uses B&S gauge, and wire uses B&S or SWG. Always select the correct tab for your material.

2

Find the Gauge Number

Locate your gauge number in the left column of the table. Remember — higher gauge = thinner material. Gauge 8 is much thicker than Gauge 28 for all metals.

3

Read mm or Inches

Read the thickness in mm (for Indian and metric use) or inches (for US/imperial specifications or older IS drawings). Both values are in the same row.

4

Check Weight per m²

The kg/m² column lets you estimate procurement weight directly. Multiply kg/m² by total sheet area to get order weight without a separate calculator.

5

Verify with Supplier

In India, some local/secondary suppliers use non-standard gauge labelling. Always cross-verify with a digital vernier calliper or micrometer at delivery to confirm the actual thickness.

6

Use the Weight Calculator

Once you have the thickness in mm, use our MS Sheet Weight Calculator or the formula below to calculate total material weight for your order.

Gauge Conversion Formula & Quick Reference

How to convert gauge to mm, inches, and weight — with worked examples for India

mm to Inches: Thickness (Inches) = Thickness (mm) ÷ 25.4
Inches to mm: Thickness (mm) = Thickness (Inches) × 25.4
Weight (kg/m²) = Thickness (mm) × Density (g/cm³)
Total Weight (kg) = Length (m) × Width (m) × Thickness (mm) × Density
Density: MS Steel = 7.85 | Stainless SS304 = 7.93 | Aluminium = 2.70 | Copper = 8.96 | GI Steel = 7.85 (g/cm³)
EXAMPLE 1

MS Sheet – Gauge 18 → mm

From table: Gauge 18 MS = 1.214 mm
In inches: 1.214 ÷ 25.4 = 0.0478″
Weight: 1.214 × 7.85 = 9.53 kg/m²

EXAMPLE 2

GI Sheet – Gauge 22 → Total Weight

Gauge 22 GI = 0.853 mm
Sheet size: 2.44 × 1.22 m = 2.977 m²
Weight: 0.853 × 7.85 × 2.977 = ≈ 19.92 kg/sheet

EXAMPLE 3

Aluminium Sheet – Gauge 14 → Weight

Gauge 14 Al (B&S) = 1.628 mm
Weight/m²: 1.628 × 2.70 = 4.40 kg/m²
8×4 ft sheet: 4.40 × 2.977 = ≈ 13.10 kg

QUICK RULE

Steel Weight Shortcut

For any steel sheet, multiply thickness in mm by 7.85 to get kg/m². Example: 2 mm steel = 2 × 7.85 = 15.70 kg/m². This works for MS, GI, and stainless steel (use 7.93 for SS304).

Why Different Metals Have Different Gauge Systems:
The gauge system was developed independently for different industries in the 19th century. There is no single universal gauge standard — US Standard Gauge (USG) applies to steel sheets, B&S gauge to non-ferrous metals and wire, and SWG to British/Indian standard wire. Always confirm which system your drawing or supplier is using before converting.

Gauge System Reference – Which to Use for Which Metal

Quick guide to selecting the correct gauge standard for different metals used in India

Mild Steel (MS)
USG
US Standard Gauge
Used for MS sheets, HR/CR sheets. Density 7.85 g/cm³
Galvanized Steel (GI)
USG+
US Standard Gauge
Same system as MS but slightly thicker due to zinc. IS 277:2018
Stainless Steel (SS)
USS
SS Sheet Gauge
Own gauge standard. SS304 density 7.93, SS316 density 7.98 g/cm³
Aluminium Sheet
B&S
Brown & Sharp Gauge
Non-ferrous sheet standard. Density 2.70 g/cm³
Copper Wire/Sheet
B&S
Brown & Sharp Gauge
Standard for electrical copper. Density 8.96 g/cm³
Binding / GI Wire
SWG
Standard Wire Gauge
British/Indian standard wire gauge. Commonly used in Indian construction

Where Gauge to mm Conversion is Used in India

Key industries and professions that rely on gauge to mm conversion charts daily

Construction & Fabrication

Fabricators and site engineers in India use gauge to mm charts daily to verify GI sheet, MS plate, and stainless sheet specifications from supplier datasheets and project drawings.

Electrical & Switchgear

Electrical panel manufacturers specify sheet thickness in gauge (Gauge 16, 18, 20). Electricians and QC engineers use this chart to verify actual mm thickness of enclosures and trays.

Automotive Industry

Body panel and chassis fabricators in Indian auto ancillary units work with gauge-specified CR/GI sheets. Converting to mm ensures compatibility with press tool and bending machine settings.

Steel Procurement

Purchase managers and material buyers use gauge to mm charts when comparing quotes from multiple suppliers who may use different unit references (gauge vs mm vs inches).

Engineering Drawings

Older IS and imported drawings often specify thickness in gauge or inches. Draughtsmen and design engineers convert these to mm for IS-standard fabrication shops across India.

Sheet Metal Workshops

Local sheet metal shops (press, roll-forming, roofing) use gauge charts to set machine clearances, select bending radii, and communicate specifications with customers and raw material suppliers.

Pro Tips for Gauge Conversion in India

Practical advice for engineers, buyers, and fabricators working with sheet metal gauges

Never Assume One Gauge System for All Metals

The biggest mistake in Indian fabrication shops is using the MS gauge table for stainless or aluminium sheets. A Gauge 18 MS sheet is 1.214 mm, but Gauge 18 stainless is 1.270 mm and Gauge 18 aluminium (B&S) is 1.024 mm — always select the correct material tab.

Always Measure with a Micrometer

In the Indian secondary steel market, sheets labelled as "Gauge 18" may actually be 1.0–1.15 mm due to under-rolling. Use a digital micrometer or vernier calliper at goods receipt to verify actual thickness before accepting delivery.

Quote in mm, Not Gauge, for Contracts

When writing purchase orders or fabrication contracts in India, always specify thickness in mm with tolerance (e.g., 1.214 mm ±0.05 mm) rather than gauge number. This prevents disputes and ensures you receive IS-compliant material.

Verify Weight to Catch Under-Gauge Sheets

Weigh a sample sheet and calculate expected weight from the gauge table (kg/m² × sheet area). If actual weight is more than 5% below the theoretical value, the sheet is likely under-gauge. This is a common quality issue in unorganised Indian steel markets.

Indian Drawings May Use SWG for Wire

Many Indian structural and electrical drawings specify wire gauge in SWG (e.g., "8 SWG binding wire"). Use the Wire tab above to convert SWG to mm. Do not confuse SWG with B&S — an 8 SWG wire is 4.064 mm, while 8 B&S wire is 3.264 mm.

Bookmark or Print This Chart

Save this page to your phone's home screen for quick site access. Site engineers, quality inspectors, and purchase teams across India keep this gauge to mm chart handy for daily material verification. No app or login required.

Related Calculators & Charts

More steel gauge and weight tools on SheetGauge India

Frequently Asked Questions

Common questions about gauge to mm and inches conversion answered for India

What is Gauge 18 in mm for steel sheet in India?
For mild steel (MS) sheet, Gauge 18 = 1.214 mm (US Standard Gauge). For galvanized (GI) sheet, Gauge 18 = 1.310 mm (slightly thicker due to zinc coating). For stainless steel, Gauge 18 = 1.270 mm. Always confirm the metal type before using a gauge to mm conversion table.
What is the difference between B&S gauge and SWG gauge?
B&S (Brown & Sharp) is the American Wire Gauge (AWG) system used for non-ferrous metals — copper wire, aluminium wire, and aluminium sheet. SWG (Standard Wire Gauge) is the British/Imperial system used for steel wire, GI binding wire, and some copper conductors in India and the UK. The two are different at every gauge number — for example, 18 B&S = 1.024 mm, but 18 SWG = 1.219 mm. India uses SWG for binding wire and B&S for electrical copper wire.
What gauge is 1mm mild steel sheet?
1 mm MS sheet is closest to Gauge 19 (0.912 mm) or Gauge 20 (0.912 mm) in the US Standard Gauge system, but there is no exact gauge number for 1.000 mm MS sheet. In India, 1 mm MS sheet is commonly sold as a nominal 1.0 mm thickness — suppliers quote it as 1 mm, not by gauge. Use the formula: Weight = 1.0 × 7.85 = 7.85 kg/m² for a 1 mm MS sheet.
Is Gauge 16 thicker than Gauge 18?
Yes. Gauge 16 is thicker than Gauge 18 for all metals. In the gauge system, lower number = thicker material. For MS sheet: Gauge 16 = 1.519 mm vs Gauge 18 = 1.214 mm. For GI sheet: Gauge 16 = 1.613 mm vs Gauge 18 = 1.310 mm. This inverse relationship is one of the most common sources of confusion in Indian fabrication shops — always remember: the smaller the gauge number, the thicker the sheet.
What gauge is 2mm MS plate in India?
2 mm MS sheet/plate falls between Gauge 14 (1.897 mm) and Gauge 13 (2.278 mm) in the US Standard Gauge system. There is no exact gauge for 2.0 mm MS. In India, 2 mm plate is always quoted as "2 mm" by suppliers — it is not sold or referenced by gauge number. Use weight formula: 2.0 × 7.85 = 15.70 kg/m².
Which gauge chart should I use for aluminium sheets in India?
For aluminium sheets, use the B&S (Brown & Sharp) gauge table — the Aluminium tab on this page. Do not use the MS/US Standard Gauge table for aluminium. For example, Gauge 14 aluminium (B&S) = 1.628 mm, while Gauge 14 MS (USG) = 1.897 mm — a significant difference. Indian aluminium sheet suppliers (Mumbai, Ahmedabad, Chennai) quote by B&S gauge or directly in mm.
How many mm is 1 inch? Quick reference for sheet metal conversion.
1 inch = 25.4 mm exactly. To convert any gauge thickness from inches to mm, multiply by 25.4. Example: Gauge 18 MS = 0.0478 inches × 25.4 = 1.214 mm. To go from mm to inches, divide by 25.4. Example: 1.310 mm ÷ 25.4 = 0.0516 inches (Gauge 18 GI sheet).